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• OpenBSD configuration: Client unable to automount via NFS using amd

  - by Rilindo

  What I am trying to do is to have my openBSD client (OpenBSD 4.9) auto mount a Linux NFS file system (Scientific Linux 6.1). So far, I am not sure if it is configured correctly. To get things out of the way, I am able to mount nfs manually: # mount_nfs -T -3 192.168.15.100:/exports /mnt # ls -la /mnt total 52 drwxr-xr-x 7 root wheel 4096 Oct 4 22:42 . drwxr-xr-x 16 root wheel 512 Nov 26 16:33 .. drwxrwxr-x 5 _sndio _sndio 4096 Oct 31 21:58 centos drwxr-xr-x 15 root wheel 4096 Nov 6 09:17 home drwxr-xr-x 5 root wheel 4096 Oct 31 21:27 sl drwxr-xr-x 3 root wheel 4096 Nov 19 16:02 sles drwxr-xr-x 17 503 503 4096 Nov 10 17:37 users # So connectivity is not an issue, as far as I can tell. As per man page, the following is configured in /etc/amd/auto.home: /defaults type:=nfs;sublink:=${key};opts:=rw,soft,intr,vers=3,proto=tcp * rhost:=192.168.15.100;rfs:=/exports In turn, /etc/amd/master is configured as such: # cat /etc/amd/master /exports amd.home Upon reboot, I can it see mount, but curiously enough, instead of the hostname: amd:24490 0 0 0 100% /exports From what I understand, amd acts a little different from FreeBSD. Still, I tried to see if I it can automount. Nope: ksh: cd: /exports/users - Resource temporarily unavailable # cd /exports/192.168.15.100/host/users ksh: cd: /exports/192.168.15.100/host/users - Resource temporarily unavailable A search in google doesn't help too much - it seems that automounting NFS with OpenBSD is not something that is usually done. Other than this, information is fairly sparse. I can, of course, always mount is permanently, but I tend to be a bit anal on convention, so no for now. :) Some direction would be appreciation. (And oh, in case you are a wondering, I tried FreeBSD way of using amd and that hasn't worked out - although I wouldn't mind an explanation of the difference between how FreeBSD implements and how OpenBSD implements it) UPDATE: After re-writing the map file several times, I got as far as actually communicating with the NFS server with this configuration: /defaults type:=nfs;rhost:=kerberos.monzell.com;rfs:=/exports;\ sublink:=${key};opts:=rw,nodev,nosuid,soft,intr,tcp,resvport * ${host}==${rhost};type:=nfs;fs:=${rfs};opts:=rw,nodev,nosuid,soft,intr,tcp,resvport However, for some reason, it seems that amd will only default to NFS version 2 over udp: # tcpdump dst kerberos tcpdump: listening on pcn0, link-type EN10MB tcpdump: WARNING: compensating for unaligned libpcap packets 20:38:28.558385 openbsd.monzell.com.856 > kerberos.monzell.com.sunrpc: udp 100 20:38:28.559154 openbsd.monzell.com.856 > kerberos.monzell.com.892: udp 96 20:38:30.592761 openbsd.monzell.com.856 > kerberos.monzell.com.nfsd: xid 0x22000000 (NFSv2) 40 null 20:38:33.558107 arp reply openbsd.monzell.com is-at 52:54:00:52:8f:66 I tried various options of forcing it to try to mount as nfsv3 such as: /defaults type:=nfs;rhost:=kerberos.monzell.com;rfs:=/exports;\ sublink:=${key};opts:=rw,nodev,nosuid,soft,intr,vers=3,proto=tcp,resvport * ${host}==${rhost};type:=nfs;fs:=${rfs};opts:=rw,nodev,nosuid,soft,intr,vers=3,proto=tcp,resvport or: /defaults type:=nfs;rhost:=kerberos.monzell.com;rfs:=/exports;\ sublink:=${key};opts:=rw,nodev,nosuid,soft,intr,vers=-3,proto=tcp,resvport * ${host}==${rhost};type:=nfs;fs:=${rfs};opts:=rw,nodev,nosuid,soft,intr,vers=3,proto=tcp,resvport Nothing yet still. Curious enough, OpenBSD mounts defaults to version 3, so I am not sure why it would start with version in amd. What would be the correct options to pass?

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• LINQ und ArcObjects

  - by Marko Apfel

  LINQ und ArcObjects Motivation LINQ1 (language integrated query) ist eine Komponente des Microsoft .NET Frameworks seit der Version 3.5. Es erlaubt eine SQL-ähnliche Abfrage zu verschiedenen Datenquellen wie SQL, XML u.v.m. Wie SQL auch, bietet LINQ dazu eine deklarative Notation der Problemlösung - d.h. man muss nicht im Detail beschreiben wie eine Aufgabe, sondern was überhaupt zu lösen ist. Das befreit den Entwickler abfrageseitig von fehleranfälligen Iterator-Konstrukten. Ideal wäre es natürlich auf diese Möglichkeiten auch in der ArcObjects-Programmierung mit Features zugreifen zu können. Denkbar wäre dann folgendes Konstrukt: var largeFeatures = from feature in features where (feature.GetValue("SHAPE_Area").ToDouble() > 3000) select feature; bzw. dessen Äquivalent als Lambda-Expression: var largeFeatures = features.Where(feature => (feature.GetValue("SHAPE_Area").ToDouble() > 3000)); Dazu muss ein entsprechender Provider zu Verfügung stehen, der die entsprechende Iterator-Logik managt. Dies ist leichter als man auf den ersten Blick denkt - man muss nur die gewünschten Entitäten als IEnumerable<IFeature> liefern. (Anm.: nicht wundern - die Methoden GetValue() und ToDouble() habe ich nebenbei als Erweiterungsmethoden deklariert.) Im Hintergrund baut LINQ selbständig eine Zustandsmaschine (state machine)2 auf deren Ausführung verzögert ist (deferred execution)3 - d.h. dass erst beim tatsächlichen Anfordern von Entitäten (foreach, Count(), ToList(), ..) eine Instanziierung und Verarbeitung stattfindet, obwohl die Zuweisung schon an ganz anderer Stelle erfolgte. Insbesondere bei mehrfacher Iteration durch die Entitäten reibt man sich bei den ersten Debuggings verwundert die Augen wenn der Ausführungszeiger wie von Geisterhand wieder in die Iterator-Logik springt. Realisierung Eine ganz knappe Logik zum Konstruieren von IEnumerable<IFeature> lässt sich mittels Durchlaufen eines IFeatureCursor realisieren. Dazu werden die einzelnen Feature mit yield ausgegeben. Der einfachen Verwendung wegen, habe ich die Logik in eine Erweiterungsmethode GetFeatures() für IFeatureClass aufgenommen: public static IEnumerable GetFeatures(this IFeatureClass featureClass, IQueryFilter queryFilter, RecyclingPolicy policy) { IFeatureCursor featureCursor = featureClass.Search(queryFilter, RecyclingPolicy.Recycle == policy); IFeature feature; while (null != (feature = featureCursor.NextFeature())) { yield return feature; } //this is skipped in unit tests with cursor-mock if (Marshal.IsComObject(featureCursor)) { Marshal.ReleaseComObject(featureCursor); } } Damit kann man sich nun ganz einfach die IEnumerable<IFeature> erzeugen lassen: IEnumerable features = _featureClass.GetFeatures(RecyclingPolicy.DoNotRecycle); Etwas aufpassen muss man bei der Verwendung des "Recycling-Cursors". Nach einer verzögerten Ausführung darf im selben Kontext nicht erneut über die Features iteriert werden. In diesem Fall wird nämlich nur noch der Inhalt des letzten (recycelten) Features geliefert und alle Features sind innerhalb der Menge gleich. Kritisch würde daher das Konstrukt largeFeatures.ToList(). ForEach(feature => Debug.WriteLine(feature.OID)); weil ToList() schon einmal durch die Liste iteriert und der Cursor somit einmal durch die Features bewegt wurde. Die Erweiterungsmethode ForEach liefert dann immer dasselbe Feature. In derartigen Situationen darf also kein Cursor mit Recycling verwendet werden. Ein mehrfaches Ausführen von foreach ist hingegen kein Problem weil dafür jedes Mal die Zustandsmaschine neu instanziiert wird und somit der Cursor neu durchlaufen wird – das ist die oben schon erwähnte Magie. Ausblick Nun kann man auch einen Schritt weiter gehen und ganz eigene Implementierungen für die Schnittstelle IEnumerable<IFeature> in Angriff nehmen. Dazu müssen nur die Methode und das Property zum Zugriff auf den Enumerator ausprogrammiert werden. Im Enumerator selbst veranlasst man in der Reset()-Methode das erneute Ausführen der Suche – dazu übergibt man beispielsweise ein entsprechendes Delegate in den Konstruktur: new FeatureEnumerator( _featureClass, featureClass => featureClass.Search(_filter, isRecyclingCursor)); und ruft dieses beim Reset auf: public void Reset() {     _featureCursor = _resetCursor(_t); } Auf diese Art und Weise können Enumeratoren für völlig verschiedene Szenarien implementiert werden, die clientseitig restlos identisch nach obigen Schema verwendet werden. Damit verschmelzen Cursors, SelectionSets u.s.w. zu einer einzigen Materie und die Wiederverwendbarkeit von Code steigt immens. Obendrein lässt sich ein IEnumerable in automatisierten Unit-Tests sehr einfach mocken - ein großer Schritt in Richtung höherer Software-Qualität.4 Fazit Nichtsdestotrotz ist Vorsicht mit diesen Konstrukten in performance-relevante Abfragen geboten. Dadurch dass im Hintergrund eine Zustandsmaschine verwalten wird, entsteht einiges an Overhead dessen Verarbeitung zusätzliche Zeit kostet - ca. 20 bis 100 Prozent. Darüber hinaus ist auch das Arbeiten ohne Recycling schnell ein Performance-Gap. Allerdings ist deklarativer LINQ-Code viel eleganter, fehlerfreier und wartungsfreundlicher als das manuelle Iterieren, Vergleichen und Aufbauen einer Ergebnisliste. Der Code-Umfang verringert sich erfahrungsgemäß im Schnitt um 75 bis 90 Prozent! Dafür warte ich gerne ein paar Millisekunden länger. Wie so oft muss abgewogen werden zwischen Wartbarkeit und Performance - wobei für mich Wartbarkeit zunehmend an Priorität gewinnt. Zumeist ist sowieso nicht der Code sondern der Anwender die Bremse im Prozess. Demo-Quellcode support.esri.de   [1] Wikipedia: LINQ http://de.wikipedia.org/wiki/LINQ [2] Wikipedia: Zustandsmaschine http://de.wikipedia.org/wiki/Endlicher_Automat [3] Charlie Calverts Blog: LINQ and Deferred Execution http://blogs.msdn.com/b/charlie/archive/2007/12/09/deferred-execution.aspx [4] Clean Code Developer - gelber Grad/Automatisierte Unit Tests http://www.clean-code-developer.de/Gelber-Grad.ashx#Automatisierte_Unit_Tests_8

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• How to Customize Fonts and Colors for Gnome Panels in Ubuntu Linux

  - by The Geek

  Earlier this week we showed you how to make the Gnome Panels totally transparent, but you really need some customized fonts and colors to make the effect work better. Here’s how to do it. This article is the first part of a multi-part series on how to customize the Ubuntu desktop, written by How-To Geek reader and ubergeek, Omar Hafiz. Changing the Gnome Colors the Easy Way You’ll first need to install Gnome Color Chooser which is available in the default repositories (the package name is gnome-color-chooser). Then go to System > Preferences > Gnome Color Chooser to launch the program. When you see all these tabs you immediately know that Gnome Color Chooser does not only change the font color of the panel, but also the color of the fonts all over Ubuntu, desktop icons, and many other things as well. Now switch to the panel tab, here you can control every thing about your panels. You can change font, font color, background and background color of the panels and start menus. Tick the “Normal” option and choose the color you want for the panel font. If you want you can change the hover color of the buttons on the panel by too. A little below the color option is the font options, this includes the font, font size, and the X and Y positioning of the font. The first two options are pretty straight forward, they change the typeface and the size. The X-Padding and Y-Padding may confuse you but they are interesting, they may give a nice look for your panels by increasing the space between items on your panel like this: X-Padding:   Y-Padding:   The bottom half of the window controls the look of your start menus which is the Applications, Places, and Systems menus. You can customize them just the way you did with the panel.   Alright, this was the easy way to change the font of your panels. Changing the Gnome Theme Colors the Command-Line Way The other hard (not so hard really) way will be changing the configuration files that tell your panel how it should look like. In your Home Folder, press Ctrl+H to show the hidden files, now find the file “.gtkrc-2.0”, open it and insert this line in it. If there are any other lines in the file leave them intact. include “/home/<username>/.gnome2/panel-fontrc” Don’t forget to replace the <user_name> with you user account name. When done close and save the file. Now navigate the folder “.gnome2” from your Home Folder and create a new file and name it “panel-fontrc”. Open the file you just created with a text editor and paste the following in it: style “my_color”{fg[NORMAL] = “#FF0000”}widget “*PanelWidget*” style “my_color”widget “*PanelApplet*” style “my_color” This text will make the font red. If you want other colors you’ll need to replace the Hex value/HTML Notation (in this case #FF0000) with the value of the color you want. To get the hex value you can use GIMP, Gcolor2 witch is available in the default repositories or you can right-click on your panel > Properties > Background tab then click to choose the color you want and copy the Hex value. Don’t change any other thing in the text. When done, save and close. Now press Alt+F2 and enter “killall gnome-panel” to force it to restart or you can log out and login again. Most of you will prefer the first way of changing the font and color for it’s ease of applying and because it gives you much more options but, some may not have the ability/will to download and install a new program on their machine or have reasons of their own for not to using it, that’s why we provided the two way. Latest Features How-To Geek ETC How to Enable User-Specific Wireless Networks in Windows 7 How to Use Google Chrome as Your Default PDF Reader (the Easy Way) How To Remove People and Objects From Photographs In Photoshop Ask How-To Geek: How Can I Monitor My Bandwidth Usage? Internet Explorer 9 RC Now Available: Here’s the Most Interesting New Stuff Here’s a Super Simple Trick to Defeating Fake Anti-Virus Malware The Splendiferous Array of Culinary Tools [Infographic] Add a Real-Time Earth Wallpaper App to Ubuntu with xplanetFX The Citroen GT – An Awesome Video Game Car Brought to Life [Video] Final Man vs. Machine Round of Jeopardy Unfolds; Watson Dominates Give Chromium-Based Browser Desktop Notifications a Native System Look in Ubuntu Chrome Time Track Is a Simple Task Time Tracker

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• Some non-generic collections

  - by Simon Cooper

  Although the collections classes introduced in .NET 2, 3.5 and 4 cover most scenarios, there are still some .NET 1 collections that don't have generic counterparts. In this post, I'll be examining what they do, why you might use them, and some things you'll need to bear in mind when doing so. BitArray System.Collections.BitArray is conceptually the same as a List<bool>, but whereas List<bool> stores each boolean in a single byte (as that's what the backing bool[] does), BitArray uses a single bit to store each value, and uses various bitmasks to access each bit individually. This means that BitArray is eight times smaller than a List<bool>. Furthermore, BitArray has some useful functions for bitmasks, like And, Xor and Not, and it's not limited to 32 or 64 bits; a BitArray can hold as many bits as you need. However, it's not all roses and kittens. There are some fundamental limitations you have to bear in mind when using BitArray: It's a non-generic collection. The enumerator returns object (a boxed boolean), rather than an unboxed bool. This means that if you do this: foreach (bool b in bitArray) { ... } Every single boolean value will be boxed, then unboxed. And if you do this: foreach (var b in bitArray) { ... } you'll have to manually unbox b on every iteration, as it'll come out of the enumerator an object. Instead, you should manually iterate over the collection using a for loop: for (int i=0; i<bitArray.Length; i++) { bool b = bitArray[i]; ... } Following on from that, if you want to use BitArray in the context of an IEnumerable<bool>, ICollection<bool> or IList<bool>, you'll need to write a wrapper class, or use the Enumerable.Cast<bool> extension method (although Cast would box and unbox every value you get out of it). There is no Add or Remove method. You specify the number of bits you need in the constructor, and that's what you get. You can change the length yourself using the Length property setter though. It doesn't implement IList. Although not really important if you're writing a generic wrapper around it, it is something to bear in mind if you're using it with pre-generic code. However, if you use BitArray carefully, it can provide significant gains over a List<bool> for functionality and efficiency of space. OrderedDictionary System.Collections.Specialized.OrderedDictionary does exactly what you would expect - it's an IDictionary that maintains items in the order they are added. It does this by storing key/value pairs in a Hashtable (to get O(1) key lookup) and an ArrayList (to maintain the order). You can access values by key or index, and insert or remove items at a particular index. The enumerator returns items in index order. However, the Keys and Values properties return ICollection, not IList, as you might expect; CopyTo doesn't maintain the same ordering, as it copies from the backing Hashtable, not ArrayList; and any operations that insert or remove items from the middle of the collection are O(n), just like a normal list. In short; don't use this class. If you need some sort of ordered dictionary, it would be better to write your own generic dictionary combining a Dictionary<TKey, TValue> and List<KeyValuePair<TKey, TValue>> or List<TKey> for your specific situation. ListDictionary and HybridDictionary To look at why you might want to use ListDictionary or HybridDictionary, we need to examine the performance of these dictionaries compared to Hashtable and Dictionary<object, object>. For this test, I added n items to each collection, then randomly accessed n/2 items: So, what's going on here? Well, ListDictionary is implemented as a linked list of key/value pairs; all operations on the dictionary require an O(n) search through the list. However, for small n, the constant factor that big-o notation doesn't measure is much lower than the hashing overhead of Hashtable or Dictionary. HybridDictionary combines a Hashtable and ListDictionary; for small n, it uses a backing ListDictionary, but switches to a Hashtable when it gets to 9 items (you can see the point it switches from a ListDictionary to Hashtable in the graph). Apart from that, it's got very similar performance to Hashtable. So why would you want to use either of these? In short, you wouldn't. Any gain in performance by using ListDictionary over Dictionary<TKey, TValue> would be offset by the generic dictionary not having to cast or box the items you store, something the graphs above don't measure. Only if the performance of the dictionary is vital, the dictionary will hold less than 30 items, and you don't need type safety, would you use ListDictionary over the generic Dictionary. And even then, there's probably more useful performance gains you can make elsewhere.

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• IP Micro-outages, telephone micro-outages, and CATV micro-outages

  - by Michael Graff

  This is a long and complicated question, mostly because it has been going on for 2.5 years without a solution in sight. It also is only one-third computer related, the other two-thirds are cable TV and cable-phone related. Background I have COX Communications for a cable provider, and we get Internet, digital cable TV, and digital phone service through them. The Internet is a SB5101 right now, and has been a DPC2100 and SB5120 in the past. Same results. The phone service is provided through a telephone interface mounted on the outside of the house (not classic VoIP) and the CATV is through a Scientific Atlanta receiver without DVR. I do have a TiVo connected to the CATV box. Symptoms The CATV shows "blocking" -- sometimes very very short duration where a few blocks appear on the screen. Sometimes it lasts long enough that the video "pauses" for 2-5 seconds, and rarely but not unseen the audio also fails. The CATV decoder box shows no correctable (FEC) or uncorrectable errors. That is, all BER counters are zero for the video stream. The Internet shows "micro-outages" where it appears that sent packets are not making it out, but I continue to receive packets from local modems. That is, pings stop coming back, but I continue to see modems broadcast for DHCP, and sometimes they ask more than once. The cable modem shows no errors during this time, but cable modems lie like you would not believe. It is actually possible to unplug the coax from the modem for 20 seconds and it reports NO ERRORS to the provider's tools. The phone service cuts out for 1-3 seconds, infrequently. When this happens, I hear NOTHING (not even comfort noise) and the remote side hears a "click" as if I were getting a call waiting message. However, there is no call incoming, other than the one I'm currently on of course. Things SEEM to happen more frequently when the temperature outside swings from cold to warm, so fall/spring seems worse than summer/winter. All micro-outages occur between once or twice a day (which I could ignore) to 10 times per hour. All SNR, signal levels, noise levels, etc. show very close to optimal when measured. COX's diagnosis This is a continual pain for me. Over the last 2.5 years, they have opened, "fixed" something, and closed the tickets. They close it without confirming that it is indeed better, and when I reopen they cannot do that, but instead they open a new ticket and send yet another low-level tech out to do the same signal tests and report that all is OK. I've finally gotten a line tech who has a clue and is motivated enough to pursue this with me. We have tried things like switching the local nodes over to UPS and generator power, but this does not trigger the noise. We have tried replacing all cabling, the tap outside my house, the modem, the CATV decoder -- all without resolution. Recently they have decided it is both my computer or switch, my TiVo, and my phone that are all broken and causing this issue. My debugging steps I spent the worse day of my TV-watching life yesterday and part of today. I watched live TV without the TiVo. I witnessed blocking, but it did "feel different." and was actually more severe. Some days it is better, some days it is worse, so perhaps this was just a very bad day. Today, I connected the TiVo to my DVD player, and ran two very long movies through it. I saw no blocking at all during nearly 6 hours of video. Suggestions? Does anyone have any suggestions on what to do next? I understand perhaps only the IP side can be addressed here, but it is one of the more limiting debugging options.

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• Call to daemon in a /etc/init.d script is blocking, not running in background

  - by tony

  I have a Perl script that I want to daemonize. Basically this perl script will read a directory every 30 seconds, read the files that it finds and then process the data. To keep it simple here consider the following Perl script (called synpipe_server, there is a symbolic link of this script in /usr/sbin/) : #!/usr/bin/perl use strict; use warnings; my $continue = 1; $SIG{'TERM'} = sub { $continue = 0; print "Caught TERM signal\n"; }; $SIG{'INT'} = sub { $continue = 0; print "Caught INT signal\n"; }; my $i = 0; while ($continue) { #do stuff print "Hello, I am running " . ++$i . "\n"; sleep 3; } So this script basically prints something every 3 seconds. Then, as I want to daemonize this script, I've also put this bash script (also called synpipe_server) in /etc/init.d/ : #!/bin/bash # synpipe_server : This starts and stops synpipe_server # # chkconfig: 12345 12 88 # description: Monitors all production pipelines # processname: synpipe_server # pidfile: /var/run/synpipe_server.pid # Source function library. . /etc/rc.d/init.d/functions pname="synpipe_server" exe="/usr/sbin/synpipe_server" pidfile="/var/run/${pname}.pid" lockfile="/var/lock/subsys/${pname}" [ -x $exe ] || exit 0 RETVAL=0 start() { echo -n "Starting $pname : " daemon ${exe} RETVAL=$? PID=$! echo [ $RETVAL -eq 0 ] && touch ${lockfile} echo $PID > ${pidfile} } stop() { echo -n "Shutting down $pname : " killproc ${exe} RETVAL=$? echo if [ $RETVAL -eq 0 ]; then rm -f ${lockfile} rm -f ${pidfile} fi } restart() { echo -n "Restarting $pname : " stop sleep 2 start } case "$1" in start) start ;; stop) stop ;; status) status ${pname} ;; restart) restart ;; *) echo "Usage: $0 {start|stop|status|restart}" ;; esac exit 0 So, (if I have well understood the doc for daemon) the Perl script should run in the background and the output should be redirected to /dev/null if I execute : service synpipe_server start But here is what I get instead : [root@master init.d]# service synpipe_server start Starting synpipe_server : Hello, I am running 1 Hello, I am running 2 Hello, I am running 3 Hello, I am running 4 Caught INT signal [ OK ] [root@master init.d]# So it starts the Perl script but runs it without detaching it from the current terminal session, and I can see the output printed in my console ... which is not really what I was expecting. Moreover, the PID file is empty (or with a line feed only, no pid returned by daemon). Does anyone have any idea of what I am doing wrong ? EDIT : maybe I should say that I am on a Red Hat machine. Scientific Linux SL release 5.4 (Boron) Would it do the job if instead of using the daemon function, I use something like : nohup ${exe} >/dev/null 2>&1 & in the init script ?

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• What to do after a servicing fails on TFS 2010

  - by Martin Hinshelwood

  What do you do if you run a couple of hotfixes against your TFS 2010 server and you start to see seem odd behaviour? A customer of mine encountered that very problem, but they could not just, or at least not easily, go back a version.   You see, around the time of the TFS 2010 launch this company decided to upgrade their entire 250+ development team from TFS 2008 to TFS 2010. They encountered a few problems, owing mainly to the size of their TFS deployment, and the way they were using TFS. They were not doing anything wrong, but when you have the largest deployment of TFS outside of Microsoft you tend to run into problems that most people will never encounter. We are talking half a terabyte of source control in TFS with over 80 proxy servers. Its certainly the largest deployment I have ever heard of. When they did their upgrade way back in April, they found two major flaws in the product that meant that they had to back out of the upgrade and wait for a couple of hotfixes. KB983504 – Hotfix KB983578 – Patch KB2401992 -Hotfix In the time since they got the hotfixes they have run 6 successful trial migrations, but we are not talking minutes or hours here. When you have 400+ GB of data it takes time to copy it around. It takes time to do the upgrade and it takes time to do a backup. Well, last week it was crunch time with their developers off for Christmas they had a window of opportunity to complete the upgrade. Now these guys are good, but they wanted Northwest Cadence to be available “just in case”. They did not expect any problems as they already had 6 successful trial upgrades. The problems surfaced around 20 hours in after the first set of hotfixes had been applied. The new Team Project Collection, the only thing of importance, had disappeared from the Team Foundation Server Administration console. The collection would not reattach either. It would not even list the new collection as attachable! Figure: We know there is a database there, but it does not This was a dire situation as 20+ hours to repeat would leave the customer over time with 250+ developers sitting around doing nothing. We tried everything, and then we stumbled upon the command of last resort. TFSConfig Recover /ConfigurationDB:SQLServer\InstanceName;TFS_ConfigurationDBName /CollectionDB:SQLServer\instanceName;"Collection Name" -http://msdn.microsoft.com/en-us/library/ff407077.aspx WARNING: Never run this command! Now this command does something a little nasty. It assumes that there really should not be anything wrong and sets about fixing it. It ignores any servicing levels in the Team Project Collection database and forcibly applies the latest version of the schema. I am sure you can imagine the types of problems this may cause when the schema is updated leaving the data behind. That said, as far as we could see this collection looked good, and we were even able to find and attach the team project collection to the Configuration database. Figure: After attaching the TPC it enters a servicing mode After reattaching the team project collection we found the message “Re-Attaching”. Well, fair enough that sounds like something that may need to happen, and after checking that there was disk IO we left it to it. 14+ hours later, it was still not done so the customer raised a priority support call with MSFT and an engineer helped them out. Figure: Everything looks good, it is just offline. Tip: Did you know that these logs are not represented in the ~/Logs/* folder until they are opened once? The engineer dug around a bit and listened to our situation. He knew that we had run the dreaded “tfsconfig restore”, but was not phased. Figure: This message looks suspiciously like the wrong servicing version As it turns out, the servicing version was slightly out of sync with the schema. KB Schema Successful           KB983504 341 Yes   KB983578 344 sort of   KB2401992 360 nope   Figure: KB, Schema table with notation to its success The Schema version above represents the final end of run version for that hotfix or patch. The only way forward The problem was that the version was somewhere between 341 and 344. This is not a nice place to be in and the engineer give us the  only way forward as the removal of the servicing number from the database so that the re-attach process would apply the latest schema. if his sounds a little like the “tfsconfig recover” command then you are exactly right. Figure: Sneakily changing that 3 to a 1 should do the trick Figure: Changing the status and dropping the version should do it Now that we have done that we should be able to safely reattach and enable the Team Project Collection. Figure: The TPC is now all attached and running You may think that this is the end of the story, but it is not. After a while of mulling and seeking expert advice we came to the opinion that the database was, for want of a better term, “hosed”. There could well be orphaned data in there and the likelihood that we would have problems later down the line is pretty high. We contacted the customer back and made them aware that in all likelihood the repaired database was more like a “cut and shut” than anything else, and at the first sign of trouble later down the line was likely to split in two. So with 40+ hours invested in getting this new database ready the customer threw it away and started again. What would you do? Would you take the “cut and shut” to production and hope for the best?

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• LINQ and ArcObjects

  - by Marko Apfel

  Motivation LINQ (language integrated query) is a component of the Microsoft. NET Framework since version 3.5. It allows a SQL-like query to various data sources such as SQL, XML etc. Like SQL also LINQ to SQL provides a declarative notation of problem solving – i.e. you don’t need describe in detail how a task could be solved, you describe what to be solved at all. This frees the developer from error-prone iterator constructs. Ideally, of course, would be to access features with this way. Then this construct is conceivable: var largeFeatures = from feature in features where (feature.GetValue("SHAPE_Area").ToDouble() > 3000) select feature; or its equivalent as a lambda expression: var largeFeatures = features.Where(feature => (feature.GetValue("SHAPE_Area").ToDouble() > 3000)); This requires an appropriate provider, which manages the corresponding iterator logic. This is easier than you might think at first sight - you have to deliver only the desired entities as IEnumerable<IFeature>. LINQ automatically establishes a state machine in the background, whose execution is delayed (deferred execution) - when you are really request entities (foreach, Count (), ToList (), ..) an instantiation processing takes place, although it was already created at a completely different place. Especially in multiple iteration through entities in the first debuggings you are rubbing your eyes when the execution pointer jumps magically back in the iterator logic. Realization A very concise logic for constructing IEnumerable<IFeature> can be achieved by running through a IFeatureCursor. You return each feature via yield. For an easier usage I have put the logic in an extension method Getfeatures() for IFeatureClass: public static IEnumerable<IFeature> GetFeatures(this IFeatureClass featureClass, IQueryFilter queryFilter, RecyclingPolicy policy) { IFeatureCursor featureCursor = featureClass.Search(queryFilter, RecyclingPolicy.Recycle == policy); IFeature feature; while (null != (feature = featureCursor.NextFeature())) { yield return feature; } //this is skipped in unit tests with cursor-mock if (Marshal.IsComObject(featureCursor)) { Marshal.ReleaseComObject(featureCursor); } } So you can now easily generate the IEnumerable<IFeature>: IEnumerable<IFeature> features = _featureClass.GetFeatures(RecyclingPolicy.DoNotRecycle); You have to be careful with the recycling cursor. After a delayed execution in the same context it is not a good idea to re-iterated on the features. In this case only the content of the last (recycled) features is provided and all the features are the same in the second set. Therefore, this expression would be critical: largeFeatures.ToList(). ForEach(feature => Debug.WriteLine(feature.OID)); because ToList() iterates once through the list and so the the cursor was once moved through the features. So the extension method ForEach() always delivers the same feature. In such situations, you must not use a recycling cursor. Repeated executions of ForEach() is not a problem, because for every time the state machine is re-instantiated and thus the cursor runs again - that's the magic already mentioned above. Perspective Now you can also go one step further and realize your own implementation for the interface IEnumerable<IFeature>. This requires that only the method and property to access the enumerator have to be programmed. In the enumerator himself in the Reset() method you organize the re-executing of the search. This could be archived with an appropriate delegate in the constructor: new FeatureEnumerator<IFeatureclass>(_featureClass, featureClass => featureClass.Search(_filter, isRecyclingCursor)); which is called in Reset(): public void Reset() { _featureCursor = _resetCursor(_t); } In this manner, enumerators for completely different scenarios could be implemented, which are used on the client side completely identical like described above. Thus cursors, selection sets, etc. merge into a single matter and the reusability of code is increasing immensely. On top of that in automated unit tests an IEnumerable could be mocked very easily - a major step towards better software quality. Conclusion Nevertheless, caution should be exercised with these constructs in performance-relevant queries. Because of managing a state machine in the background, a lot of overhead is created. The processing costs additional time - about 20 to 100 percent. In addition, working without a recycling cursor is fast a performance gap. However declarative LINQ code is much more elegant, flawless and easy to maintain than manually iterating, compare and establish a list of results. The code size is reduced according to experience an average of 75 to 90 percent! So I like to wait a few milliseconds longer. As so often it has to be balanced between maintainability and performance - which for me is gaining in priority maintainability. In times of multi-core processors, the processing time of most business processes is anyway not dominated by code execution but by waiting for user input. Demo source code The source code for this prototype with several unit tests, you can download here: https://github.com/esride-apf/Linq2ArcObjects. .

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• Installing EclipseFP on Mac OS X

  - by Dom Kennedy

  I am trying to install EclipseFP. I'm running OS X Mavericks. I've tried following both the official installation instructions and the advice in this answer on SU, but I'm still having the same problem. I can get the plugin itself installed painlessly using Help -> Install New Software..., Bbut when I restart and switch to the Haskell perspective, things start to go wrong. The installation instructions tells me that I should receive a prompt to install BuildWrapper and Scion Browser. I do not receive this prompt. Furthermore, if I create a new Haskell project, my code has no syntax highlighting, and the Hoogle search feature does not appear to do anything. It's clear that the plugin is not set up correctly yet. I've tried running cabal update in Terminal, but this does not change anything. After several attempts going round in circles with this on Eclipse Juno, I uninstalled Eclispe and the Haskell Platform and performed a clean install of Eclipse Luna and the latest Haskell Platform. However, the problems are persisting. I've tried going into Preferences to see if I could sort any of this out manually. I should initially point out that my GHC installation seems to be correctly references under Preferences -> Haskell Implementations Under Haskell -> Helper executables, there are areas for configuring the options of both BuildWrapper and Scion Browser. At present, both are blank. I tried clicking the Install from Hackage... button beside each of them with no success; I receive an error message saying Expected executable <workspace>/.metadata/.plugins/net.sf.eclipsefp.haskell.ui/sandbox/.cabal-sandbox/bin/buildwrapper not found!` (replace buildwrapper for scion-browser and the message is the same) The Eclipse console displays the following exception after doing the above with BuildWrapper: src/Language/Haskell/BuildWrapper/GHCStorage.hs:313:32: Not in scope: data constructor ‘MatchGroup’ cabal.real: Error: some packages failed to install: buildwrapper-0.7.4 failed during the building phase. The exception was: ExitFailure 1 and after doing it for Scion-Browser: zip-archive-0.2.3.4 (reinstall) changes: text-1.1.0.0 -> 0.11.3.1 pandoc-1.12.3.3 (latest: 1.13) -http-conduit (new version) Graphalyze-0.14.1.0 (reinstall) changes: pandoc-1.12.4.2 -> 1.12.3.3, text-1.1.0.0 -> 0.11.3.1 cabal.real: The following packages are likely to be broken by the reinstalls: pandoc-1.12.4.2 unordered-containers-0.2.4.0 aeson-0.7.0.4 scientific-0.2.0.2 case-insensitive-1.1.0.3 HTTP-4000.2.10 Use --force-reinstalls if you want to install anyway. After receiving similar results as the above on previous attempts, I've tried using force-reinstalls and ended up at more dead ends. I am at a loss as to what is wrong and how to solve this. I should point out that my GHC installation appears to be correctly configured under Preferences -> Haskell -> Haskell Implementations. Apologies if any of this information is irrelevant, I'm just not really sure what is important and what isn't at this point. Any help anyone could provide me with would be greatly appreciated.

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• Is there a bug with Apache 2.2 and content filters (and maybe mod_proxy)?

  - by asciiphil

  I'm running Apache 2.2.15-29 on RHEL 6 (actually Scientific Linux 6.4) and I'm trying to set up a reverse proxy with content rewriting so all of the links on the proxied web pages are rewritten to reference the proxy host. I'm running into a problem with some of the content rewriting and I'd like to know if this is a bug or if I'm doing something wrong (and how to do it right, if applicable). I'm proxying a subdirectory on an internal host (internal.example.com/foo) onto the root of an external host (external.example.com). I need to rewrite HTML, CSS, and Javascript content to fix all of the URLs. I'm also hosting some content locally on the external host, which I don't think is a problem but I'm mentioning here for completeness. My httpd.conf looks roughly like this: <VirtualHost *:80> ServerName external.example.com ServerAlias example.com # Serve all local content directly, reverse-proxy all unknown URIs. RewriteEngine On RewriteRule ^(/(index.html?)?)?$ http://internal.example.com/foo/ [P] RewriteCond %{DOCUMENT_ROOT}%{REQUEST_FILENAME} -f [OR] RewriteCond %{DOCUMENT_ROOT}%{REQUEST_FILENAME} -d RewriteRule ^.*$ - [L] RewriteRule ^/~ - [L] RewriteRule ^(.*)$ http://internal.example.com$1 [P] # Standard header rewriting. ProxyPassReverse / http://internal.example.com/foo/ ProxyPassReverseCookieDomain internal.example.com external.example.com ProxyPassReverseCookiePath /foo/ / # Strip any Accept-Encoding: headers from the client so we can process the pages # as plain text. RequestHeader unset Accept-Encoding # Use mod_proxy_html to fix URLs in text/html content. ProxyHTMLEnable On ProxyHTMLURLMap http://internal.example.com/foo/ / ProxyHTMLURLMap http://internal.example.com/foo / ProxyHTMLURLMap /foo/ / ## Use mod_substitute to fix URLs in CSS and Javascript #<Location /> # AddOutputFilterByType SUBSTITUTE text/css # AddOutputFilterByType SUBSTITUTE text/javascript # Substitute "s|http://internal.example.com/foo/|/|nq" #</Location> # Use mod_ext_filter to fix URLs in CSS and Javascript ExtFilterDefine fixurlcss mode=output intype=text/css cmd="/bin/sed -rf /etc/httpd/fixurls" ExtFilterDefine fixurljs mode=output intype=text/javascript cmd="/bin/sed -rf /etc/httpd/fixurls" <Location /> SetOutputFilter fixurlcss;fixurljs </Location> </VirtualHost> The text/html rewriting works just fine. When I use either mod_substitute or mod_ext_filter, the external server sends the pages as Transfer-Encoding: chunked, sends all of the data, and then closes the connection without sending the final, zero-length chunk. Some HTTP clients are unhappy with this. (Chrome won't process any content sent in this way, for example, so the pages don't get CSS applied to them.) Here's a sample wget session: $ wget -O /dev/null -S http://external.example.com/include/jquery.js --2013-11-01 11:36:36-- http://external.example.com/include/jquery.js Resolving external.example.com (external.example.com)... 192.168.0.1 Connecting to external.example.com (external.example.com)|192.168.0.1|:80... connected. HTTP request sent, awaiting response... HTTP/1.1 200 OK Date: Fri, 01 Nov 2013 15:36:36 GMT Server: Apache Last-Modified: Tue, 29 Oct 2013 13:09:10 GMT ETag: "1d60026-187b8-4e9e0ec273e35" Accept-Ranges: bytes Vary: Accept-Encoding X-UA-Compatible: IE=edge,chrome=1 Content-Type: text/javascript;charset=utf-8 Connection: close Transfer-Encoding: chunked Length: unspecified [text/javascript] Saving to: `/dev/null' [ <=> ] 100,280 --.-K/s in 0.005s 2013-11-01 11:36:37 (19.8 MB/s) - Read error at byte 100280 (Success).Retrying. --2013-11-01 11:36:38-- (try: 2) http://external.example.com/include/jquery.js Connecting to external.example.com (external.example.com)|192.168.0.1|:80... connected. HTTP request sent, awaiting response... HTTP/1.1 416 Requested Range Not Satisfiable Date: Fri, 01 Nov 2013 15:36:38 GMT Server: Apache Vary: Accept-Encoding Content-Type: text/html;charset=utf-8 Content-Length: 260 Connection: close The file is already fully retrieved; nothing to do. Am I doing something wrong? Am I hitting some sort of Apache bug? What do I need to do to get it working? (Note that I'd prefer solutions that work within RHEL-6-packaged RPMs and upgrading to Apache 2.4 would be a last resort, as we have a lot of infrastructure built around 2.2 on this system at the moment.)

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• CodePlex Daily Summary for Thursday, March 11, 2010

  CodePlex Daily Summary for Thursday, March 11, 2010New ProjectsASP.NET Wiki Control: This ASP.NET user control allows you to embed a very useful wiki directly into your already existing ASP.NET website taking advantage of the popula...BabyLog: Log baby daily activity.buddyHome: buddyHome is a project that can make your home smarter. as good as your buddy. Cloud Community: Cloud Community makes it easier for organizations to have a simple to use community platform. Our mission is to create an easy to use community pl...Community Connectors for Microsoft CRM 4.0: Community Connectors for Microsoft CRM 4.0 allows Microsoft CRM 4.0 customers and partners to monitor and analyze customers’ interaction from their...Console Highlighter: Hightlights Microsoft Windows Command prompt (cmd.exe) by outputting ANSI VT100 Control sequences to color the output. These sequences are not hand...Cornell Store: This is IN NO WAY officially affiliated or related to the Cornell University store. Instead, this is a project that I am doing for a class. Ther...DevUtilities: This project is for creating some utility tools, and they will be useful during the development.DotNetNuke® Skin Maple: A DotNetNuke Design Challenge skin package submitted to the "Personal" category by DyNNamite.co.uk. The package includes 4 color variations and sev...HRNet: HRNetIIS Web Site Monitoring: A software for monitor a particular web site on IIS, even if its IP is sharing between different web site.Iowa Code Camp: The source code for the Iowa Code Camp website.Leonidas: Leonidas is a virtual tutorLunch 'n Learn: The Lunch 'n Learn web application is an open source ASP.NET MVC application that allows you to setup lunch 'n learn presentations for your team, c...MNT Cryptography: A very simple cryptography classMooiNooi MVC2LINQ2SQL Web Databinder: mvc2linq2sql is a databinder for ASP.NET MVC that make able developer to clean bind object from HTML FORMS to Linq entities. Even 1 to N relations ...MoqBot: MoqBot is an auto mocking library for Moq and Ninject.mtExperience1: hoiMvcPager: MvcPager is a free paging component for ASP.NET MVC web application, it exposes a series of extension methods for using in ASP.NET MVC applications...OCal: OCal is based on object calisthenics to identify code smellsPex Custom Arithmetic Solver: Pex Custom Arithmetic Solver contains a collection of meta-heuristic search algorithms. The goal is to improve Pex's code coverage for code involvi...SetControls: Расширеные контролы для ASP.NET приложений. Полная информация ближе к релизу...shadowrage1597: CTC 195 Game Design classSharePoint Team-Mailer: A SharePoint 2007 solution that defines a generic CustomList for sending e-mails to SharePoint Groups.Sql Share: SQL Share is a collaboration tool used within the science to allow database engineers to work tightly with domain scientists.TechCalendar: Tech Events Calendar ASP.NET project.ZLYScript: A very simple script language compiler.New ReleasesALGLIB: ALGLIB 2.4.0: New ALGLIB release contains: improved versions of several linear algebra algorithms: QR decomposition, matrix inversion, condition number estimatio...AmiBroker Plug-Ins with C#: AmiBroker Plug-Ins v0.0.2: Source codes and a binaryAppFabric Caching UI Admin Tool: AppFabric Caching Beta 2 UI Admin Tool: System Requirements:.NET 4.0 RC AppFabric Caching Beta2 Test On:Win 7 (64x)Autodocs - WCF REST Automatic API Documentation Generator: Autodocs.ServiceModel.Web: This archive contains the reference DLL, instructions and license.Compact Plugs & Compact Injection: Compact Injection and Compact Plugs 1.1 Beta: First release of Compact Plugs (CP). The solution includes a simple example project of CP, called "TestCompactPlugs1". Also some fixes where made ...Console Highlighter: Console Highlighter 0.9 (preview release): Preliminary release.Encrypted Notes: Encrypted Notes 1.3: This is the latest version of Encrypted Notes (1.3). It has an installer - it will create a directory 'CPascoe' in My Documents. The last one was ...Family Tree Analyzer: Version 1.0.2: Family Tree Analyzer Version 1.0.2 This early beta version implements loading a gedcom file and displaying some basic reports. These reports inclu...FRC1103 - FRC Dashboard viewer: 2010 Documentation v0.1: This is my current version of the control system documentation for 2010. It isn't complete, but it has the information required for a custom dashbo...jQuery.cssLess: jQuery.cssLess 0.5 (Even less release): NEW - support for nested special CSS classes (like :hover) MAIN RELEASE This release, code "Even less", is the one that will interpret cssLess wit...MooiNooi MVC2LINQ2SQL Web Databinder: MooiNooi MVC2LINQ2SQL DataBinder: I didn't try this... I just took it off from my project. Please, tell me any problem implementing in your own development and I'll be pleased to h...MvcPager: MvcPager 1.2 for ASP.NET MVC 1.0: MvcPager 1.2 for ASP.NET MVC 1.0Mytrip.Mvc: Mytrip 1.0 preview 1: Article Manager Blog Manager L2S Membership(.NET Framework 3.5) EF Membership(.NET Framework 4) User Manager File Manager Localization Captcha ...NodeXL: Network Overview, Discovery and Exploration for Excel: NodeXL Excel 2007 Template, version 1.0.1.117: The NodeXL Excel 2007 template displays a network graph using edge and vertex lists stored in an Excel 2007 workbook. What's NewThis version adds ...Pex Custom Arithmetic Solver: PexCustomArithmeticSolver: This is the alpha release containing the Alternating Variable Method and Evolution Strategies to try and solve constraints over floating point vari...Scrum Sprint Monitor: v1.0.0.44877: What is new in this release? Major performance increase in animations (up to 50 fps from 2 fps) by replacing DropShadow effect with png bitmaps; ...sELedit: sELedit v1.0b: + Added support for empty strings / wstrings + Fixed: critical bug in configuration files (list 53)sPWadmin: pwAdmin v0.9_nightly: + Fixed: XML editor can now open and save character templates + Added: PWI item name database + Added: Plugin SupportTechCalendar: Events Calendar v.1.0: Initial release.The Silverlight Hyper Video Player [http://slhvp.com]: Beta 2: Beta 2.0 Some fixes from Beta 1, and a couple small enhancements. Intensive testing continues, and I will continue to update the code at least ever...ThreadSafe.Caching: 2010.03.10.1: Updates to the scavanging behaviour since last release. Scavenging will now occur every 30 seconds by default and all objects in the cache will be ...VCC: Latest build, v2.1.30310.0: Automatic drop of latest buildVisual Studio DSite: Email Sender (C++): The same Email Sender program that I but made in visual c plus plus 2008 instead of visual basic 2008.Web Forms MVP: Web Forms MVP CTP7: The release can be considered stable, and is in use behind several high traffic, public websites. It has been marked as a CTP release as it is not ...White Tiger: 0.0.3.1: Now you can load or create files with whatever root element you want *check f or sets file permisionsMost Popular ProjectsMetaSharpWBFS ManagerRawrAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)ASP.NETMicrosoft SQL Server Community & SamplesASP.NET Ajax LibraryMost Active ProjectsUmbraco CMSRawrSDS: Scientific DataSet library and toolsN2 CMSFasterflect - A Fast and Simple Reflection APIjQuery Library for SharePoint Web ServicesBlogEngine.NETFarseer Physics Enginepatterns & practices – Enterprise LibraryCaliburn: An Application Framework for WPF and Silverlight

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• Observations in Migrating from JavaFX Script to JavaFX 2.0

  - by user12608080

  Observations in Migrating from JavaFX Script to JavaFX 2.0 Introduction Having been available for a few years now, there is a decent body of work written for JavaFX using the JavaFX Script language. With the general availability announcement of JavaFX 2.0 Beta, the natural question arises about converting the legacy code over to the new JavaFX 2.0 platform. This article reflects on some of the observations encountered while porting source code over from JavaFX Script to the new JavaFX API paradigm. The Application The program chosen for migration is an implementation of the Sudoku game and serves as a reference application for the book JavaFX – Developing Rich Internet Applications. The design of the program can be divided into two major components: (1) A user interface (ideally suited for JavaFX design) and (2) the puzzle generator. For the context of this article, our primary interest lies in the user interface. The puzzle generator code was lifted from a sourceforge.net project and is written entirely in Java. Regardless which version of the UI we choose (JavaFX Script vs. JavaFX 2.0), no code changes were required for the puzzle generator code. The original user interface for the JavaFX Sudoku application was written exclusively in JavaFX Script, and as such is a suitable candidate to convert over to the new JavaFX 2.0 model. However, a few notable points are worth mentioning about this program. First off, it was written in the JavaFX 1.1 timeframe, where certain capabilities of the JavaFX framework were as of yet unavailable. Citing two examples, this program creates many of its own UI controls from scratch because the built-in controls were yet to be introduced. In addition, layout of graphical nodes is done in a very manual manner, again because much of the automatic layout capabilities were in flux at the time. It is worth considering that this program was written at a time when most of us were just coming up to speed on this technology. One would think that having the opportunity to recreate this application anew, it would look a lot different from the current version. Comparing the Size of the Source Code An attempt was made to convert each of the original UI JavaFX Script source files (suffixed with .fx) over to a Java counterpart. Due to language feature differences, there are a small number of source files which only exist in one version or the other. The table below summarizes the size of each of the source files. JavaFX Script source file Number of Lines Number of Character JavaFX 2.0 Java source file Number of Lines Number of Characters ArrowKey.java 6 72 Board.fx 221 6831 Board.java 205 6508 BoardNode.fx 446 16054 BoardNode.java 723 29356 ChooseNumberNode.fx 168 5267 ChooseNumberNode.java 302 10235 CloseButtonNode.fx 115 3408 CloseButton.java 99 2883 ParentWithKeyTraversal.java 111 3276 FunctionPtr.java 6 80 Globals.java 20 554 Grouping.fx 8 140 HowToPlayNode.fx 121 3632 HowToPlayNode.java 136 4849 IconButtonNode.fx 196 5748 IconButtonNode.java 183 5865 Main.fx 98 3466 Main.java 64 2118 SliderNode.fx 288 10349 SliderNode.java 350 13048 Space.fx 78 1696 Space.java 106 2095 SpaceNode.fx 227 6703 SpaceNode.java 220 6861 TraversalHelper.fx 111 3095 Total 2,077 79,127 2531 87,800 A few notes about this table are in order: The number of lines in each file was determined by running the Unix ‘wc –l’ command over each file. The number of characters in each file was determined by running the Unix ‘ls –l’ command over each file. The examination of the code could certainly be much more rigorous. No standard formatting was performed on these files.  All comments however were deleted. There was a certain expectation that the new Java version would require more lines of code than the original JavaFX script version. As evidenced by a count of the total number of lines, the Java version has about 22% more lines than its FX Script counterpart. Furthermore, there was an additional expectation that the Java version would be more verbose in terms of the total number of characters.  In fact the preceding data shows that on average the Java source files contain fewer characters per line than the FX files.  But that's not the whole story.  Upon further examination, the FX Script source files had a disproportionate number of blank characters.  Why?  Because of the nature of how one develops JavaFX Script code.  The object literal dominates FX Script code.  Its not uncommon to see object literals indented halfway across the page, consuming lots of meaningless space characters. RAM consumption Not the most scientific analysis, memory usage for the application was examined on a Windows Vista system by running the Windows Task Manager and viewing how much memory was being consumed by the Sudoku version in question. Roughly speaking, the FX script version, after startup, had a RAM footprint of about 90MB and remained pretty much the same size. The Java version started out at about 55MB and maintained that size throughout its execution. What About Binding? Arguably, the most striking observation about the conversion from JavaFX Script to JavaFX 2.0 concerned the need for data synchronization, or lack thereof. In JavaFX Script, the primary means to synchronize data is via the bind expression (using the “bind” keyword), and perhaps to a lesser extent it’s “on replace” cousin. The bind keyword does not exist in Java, so for JavaFX 2.0 a Data Binding API has been introduced as a replacement. To give a feel for the difference between the two versions of the Sudoku program, the table that follows indicates how many binds were required for each source file. For JavaFX Script files, this was ascertained by simply counting the number of occurrences of the bind keyword. As can be seen, binding had been used frequently in the JavaFX Script version (and does not take into consideration an additional half dozen or so “on replace” triggers). The JavaFX 2.0 program achieves the same functionality as the original JavaFX Script version, yet the equivalent of binding was only needed twice throughout the Java version of the source code. JavaFX Script source file Number of Binds JavaFX Next Java source file Number of “Binds” ArrowKey.java 0 Board.fx 1 Board.java 0 BoardNode.fx 7 BoardNode.java 0 ChooseNumberNode.fx 11 ChooseNumberNode.java 0 CloseButtonNode.fx 6 CloseButton.java 0 CustomNodeWithKeyTraversal.java 0 FunctionPtr.java 0 Globals.java 0 Grouping.fx 0 HowToPlayNode.fx 7 HowToPlayNode.java 0 IconButtonNode.fx 9 IconButtonNode.java 0 Main.fx 1 Main.java 0 Main_Mobile.fx 1 SliderNode.fx 6 SliderNode.java 1 Space.fx 0 Space.java 0 SpaceNode.fx 9 SpaceNode.java 1 TraversalHelper.fx 0 Total 58 2 Conclusions As the JavaFX 2.0 technology is so new, and experience with the platform is the same, it is possible and indeed probable that some of the observations noted in the preceding article may not apply across other attempts at migrating applications. That being said, this first experience indicates that the migrated Java code will likely be larger, though not extensively so, than the original Java FX Script source. Furthermore, although very important, it appears that the requirements for data synchronization via binding, may be significantly less with the new platform.

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• CodePlex Daily Summary for Sunday, June 06, 2010

  CodePlex Daily Summary for Sunday, June 06, 2010New ProjectsActive Worlds Dot Net Wrapper (Based on AwSdk): Active Worlds Dot Net Wrapper (Based on AwSdk)Combina: Smart calculator for large combinatorial calculations.Concurrent Cache: ConcurrentCache is a smart output cache library extending OutputCacheProvider. It consists of in memory, cache files and compressed files modes and...Decay: Personal use. For learningFazTalk: FazTalk is a suite of tools and products that are designed to improve collaboration and workflow interactions. FazTalk takes an innovative approach...grouped: A peer to peer text editor, written in C# [update] I wrote this little thing a while back and even forgot about it, I stopped coding for more tha...HitchARide MVC 2 Sample: An MVC 2 sample written as part of the Microsoft 2010 London Web Camp based on the wireframes at http://schematics.earthware.co.uk/hitcharide. Not...Inspiration.Web: Description: A simple (but entertaining) ASP.NET MVC (C#) project to suggest random code names for projects. Intended audience: People who ne...NetFileBrowser - TinyMCE: tinyMCE file plugin with asp.netOil Slick Live Feeds: All live feeds from BP's Remotely Operated VehiclesParticle Lexer: Parser and Tokenizer libraryPdf Form Tool: Pdf Form Tool demonstrates how the iTextSharp library could be used to fill PDF forms. The input data is provided as a csv file. The application ...Planning Poker Windows Mobile 7: This project is a Planning Poker application for Windows Mobile 7 (and later?). RandomRat: RandomRat is a program for generating random sets that meet specific criteriaScience.NET: A scientific library written in managed code. It supports advanced mathematics (algebra system, sequences, statistics, combinatorics...), data stru...Spider Compiler: Spider Compiler parses the input of a spider programming source file and compiles it (with help of csc.exe; the C#-Compiler) to an exe-file. This p...Sununpro: sunun's project for study by team foundation server.TFS Buddy: An application that manipulates your I-Buddy whenever something happens in your Team Foundation ServerValveSoft: ValveSysWiiMote Physics: WiiMote Physics is an application that allows you to retrieve data from your WiiMote or Balance Board and display it in real-time. It has a number...WinGet: WinGet is a download manager for Windows. You can drag links onto the WinGet Widget and it will download a file on the selected folder. It is dev...XProject.NET: A project management and team collaboration platformNew Releases.NET DiscUtils: Version 0.9 Preview: This release is still under development. New features available in this release: Support for accessing short file names stored in WIM files Incr...Active Worlds Dot Net Wrapper (Based on AwSdk): Active World Dot Net Wrapper (0.0.1.85): Based on AwSdk 85AwSdk UnOfficial Wrapper Howto Use: C# using AwWrapper; VB.Net Import AwWrapperAjaxControlToolkit additional extenders: ZhecheAjaxControls for .NET3.5: Used AJAX Control Toolkit Release Notes - April 12th 2010 Release Version 40412. Fixed deadlock in long operation canceling Some other fixesAnyCAD: AnyCAD.v1.2.ENU.Install: http://www.anycad.net Parametric Modeling *3D: Sphere, Box, Cylinder, Cone •2D: Line, Rectangle, Arc, Arch, Circle, Spline, Polygon •Feature: Extr...Community Forums NNTP bridge: Community Forums NNTP Bridge V29: Release of the Community Forums NNTP Bridge to access the social and anwsers MS forums with a single, open source NNTP bridge. This release has ad...Concurrent Cache: 1.0: This is the first release for the ConcurrentCache library.Configuration Section Designer: 2.0.0: This is the first Beta Release for VS 2010 supportDoxygen Browser Addin for VS: Doxygen Browser Addin - v0.1.4 Beta: Support for Visual Studio 2010 improved the logging of errors (Event Logs) Fixed some issues/bugs Hot key for navigation "Control + F1, Contr...Folder Bookmarks: Folder Bookmarks 1.6.2: The latest version of Folder Bookmarks (1.6.2), with new UI changes. Once you have extracted the file, do not delete any files/folders. They are n...HERB.IQ: Beta 0.1 Source code release 5: Beta 0.1 Source code release 5Inspiration.Web: Initial release (deployment package): Initial release (deployment package)NetFileBrowser - TinyMCE: Demo Project: Demo ProjectNetFileBrowser - TinyMCE: NetFileBrowser: NetImageBrowserNLog - Advanced .NET Logging: Nightly Build 2010.06.05.001: Changes since the last build:2010-06-04 23:29:42 Jarek Kowalski Massive update to documentation generator. 2010-05-28 15:41:42 Jarek Kowalski upda...Oil Slick Live Feeds: Oil Slick Live Feeds 0.1: A the first release, with feeds from the MS Skandi, Boa Deep C, Enterprise and Q4000. They are live streams from the ROV's monitoring the damaged...Pcap.Net: Pcap.Net 0.7.0 (46671): Pcap.Net - June 2010 Release Pcap.Net is a .NET wrapper for WinPcap written in C++/CLI and C#. It Features almost all WinPcap features and includes...sqwarea: Sqwarea 0.0.289.0 (alpha): API supportTFS Buddy: TFS Buddy First release (Beta 1): This is the first release of the TFS Buddy.Visual Studio DSite: Looping Animation (Visual C++ 2008): A solider firing a bullet that loops and displays an explosion everytime it hits the edge of the form.WiiMote Physics: WiiMote Physics v4.0: v4.0.0.1 Recovered from existing compiled assembly after hard drive failure Now requires .NET 4.0 (it seems to make it run faster) Added new c...WinGet: Alpha 1: First Alpha of WinGet. It includes all the planned features but it contains many bugs. Packaged using 7-Zip and ClickOnce.Most Popular ProjectsWBFS ManagerRawrAJAX Control ToolkitMicrosoft SQL Server Product Samples: DatabaseSilverlight ToolkitWindows Presentation Foundation (WPF)PHPExcelpatterns & practices – Enterprise LibraryMicrosoft SQL Server Community & SamplesASP.NETMost Active ProjectsCommunity Forums NNTP bridgeRawrpatterns & practices – Enterprise LibraryGMap.NET - Great Maps for Windows Forms & PresentationN2 CMSIonics Isapi Rewrite FilterStyleCopsmark C# LibraryFarseer Physics Enginepatterns & practices: Composite WPF and Silverlight

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• Fraud Detection with the SQL Server Suite Part 2

  - by Dejan Sarka

  This is the second part of the fraud detection whitepaper. You can find the first part in my previous blog post about this topic. My Approach to Data Mining Projects It is impossible to evaluate the time and money needed for a complete fraud detection infrastructure in advance. Personally, I do not know the customer’s data in advance. I don’t know whether there is already an existing infrastructure, like a data warehouse, in place, or whether we would need to build one from scratch. Therefore, I always suggest to start with a proof-of-concept (POC) project. A POC takes something between 5 and 10 working days, and involves personnel from the customer’s site – either employees or outsourced consultants. The team should include a subject matter expert (SME) and at least one information technology (IT) expert. The SME must be familiar with both the domain in question as well as the meaning of data at hand, while the IT expert should be familiar with the structure of data, how to access it, and have some programming (preferably Transact-SQL) knowledge. With more than one IT expert the most time consuming work, namely data preparation and overview, can be completed sooner. I assume that the relevant data is already extracted and available at the very beginning of the POC project. If a customer wants to have their people involved in the project directly and requests the transfer of knowledge, the project begins with training. I strongly advise this approach as it offers the establishment of a common background for all people involved, the understanding of how the algorithms work and the understanding of how the results should be interpreted, a way of becoming familiar with the SQL Server suite, and more. Once the data has been extracted, the customer’s SME (i.e. the analyst), and the IT expert assigned to the project will learn how to prepare the data in an efficient manner. Together with me, knowledge and expertise allow us to focus immediately on the most interesting attributes and identify any additional, calculated, ones soon after. By employing our programming knowledge, we can, for example, prepare tens of derived variables, detect outliers, identify the relationships between pairs of input variables, and more, in only two or three days, depending on the quantity and the quality of input data. I favor the customer’s decision of assigning additional personnel to the project. For example, I actually prefer to work with two teams simultaneously. I demonstrate and explain the subject matter by applying techniques directly on the data managed by each team, and then both teams continue to work on the data overview and data preparation under our supervision. I explain to the teams what kind of results we expect, the reasons why they are needed, and how to achieve them. Afterwards we review and explain the results, and continue with new instructions, until we resolve all known problems. Simultaneously with the data preparation the data overview is performed. The logic behind this task is the same – again I show to the teams involved the expected results, how to achieve them and what they mean. This is also done in multiple cycles as is the case with data preparation, because, quite frankly, both tasks are completely interleaved. A specific objective of the data overview is of principal importance – it is represented by a simple star schema and a simple OLAP cube that will first of all simplify data discovery and interpretation of the results, and will also prove useful in the following tasks. The presence of the customer’s SME is the key to resolving possible issues with the actual meaning of the data. We can always replace the IT part of the team with another database developer; however, we cannot conduct this kind of a project without the customer’s SME. After the data preparation and when the data overview is available, we begin the scientific part of the project. I assist the team in developing a variety of models, and in interpreting the results. The results are presented graphically, in an intuitive way. While it is possible to interpret the results on the fly, a much more appropriate alternative is possible if the initial training was also performed, because it allows the customer’s personnel to interpret the results by themselves, with only some guidance from me. The models are evaluated immediately by using several different techniques. One of the techniques includes evaluation over time, where we use an OLAP cube. After evaluating the models, we select the most appropriate model to be deployed for a production test; this allows the team to understand the deployment process. There are many possibilities of deploying data mining models into production; at the POC stage, we select the one that can be completed quickly. Typically, this means that we add the mining model as an additional dimension to an existing DW or OLAP cube, or to the OLAP cube developed during the data overview phase. Finally, we spend some time presenting the results of the POC project to the stakeholders and managers. Even from a POC, the customer will receive lots of benefits, all at the sole risk of spending money and time for a single 5 to 10 day project: The customer learns the basic patterns of frauds and fraud detection The customer learns how to do the entire cycle with their own people, only relying on me for the most complex problems The customer’s analysts learn how to perform much more in-depth analyses than they ever thought possible The customer’s IT experts learn how to perform data extraction and preparation much more efficiently than they did before All of the attendees of this training learn how to use their own creativity to implement further improvements of the process and procedures, even after the solution has been deployed to production The POC output for a smaller company or for a subsidiary of a larger company can actually be considered a finished, production-ready solution It is possible to utilize the results of the POC project at subsidiary level, as a finished POC project for the entire enterprise Typically, the project results in several important “side effects” Improved data quality Improved employee job satisfaction, as they are able to proactively contribute to the central knowledge about fraud patterns in the organization Because eventually more minds get to be involved in the enterprise, the company should expect more and better fraud detection patterns After the POC project is completed as described above, the actual project would not need months of engagement from my side. This is possible due to our preference to transfer the knowledge onto the customer’s employees: typically, the customer will use the results of the POC project for some time, and only engage me again to complete the project, or to ask for additional expertise if the complexity of the problem increases significantly. I usually expect to perform the following tasks: Establish the final infrastructure to measure the efficiency of the deployed models Deploy the models in additional scenarios Through reports By including Data Mining Extensions (DMX) queries in OLTP applications to support real-time early warnings Include data mining models as dimensions in OLAP cubes, if this was not done already during the POC project Create smart ETL applications that divert suspicious data for immediate or later inspection I would also offer to investigate how the outcome could be transferred automatically to the central system; for instance, if the POC project was performed in a subsidiary whereas a central system is available as well Of course, for the actual project, I would repeat the data and model preparation as needed It is virtually impossible to tell in advance how much time the deployment would take, before we decide together with customer what exactly the deployment process should cover. Without considering the deployment part, and with the POC project conducted as suggested above (including the transfer of knowledge), the actual project should still only take additional 5 to 10 days. The approximate timeline for the POC project is, as follows: 1-2 days of training 2-3 days for data preparation and data overview 2 days for creating and evaluating the models 1 day for initial preparation of the continuous learning infrastructure 1 day for presentation of the results and discussion of further actions Quite frequently I receive the following question: are we going to find the best possible model during the POC project, or during the actual project? My answer is always quite simple: I do not know. Maybe, if we would spend just one hour more for data preparation, or create just one more model, we could get better patterns and predictions. However, we simply must stop somewhere, and the best possible way to do this, according to my experience, is to restrict the time spent on the project in advance, after an agreement with the customer. You must also never forget that, because we build the complete learning infrastructure and transfer the knowledge, the customer will be capable of doing further investigations independently and improve the models and predictions over time without the need for a constant engagement with me.

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• Getting your bearings and defining the project objective

  - by johndoucette

  I wrote this two years ago and thought it was worth posting… Some may think this is a daunting task and some may even say “what a waste of time” and want to open MS Project and start typing out tasks because someone asked for an estimate and a task list. Hell, maybe you even use Excel and pump out a spreadsheet with some real scientific formula for guessing how long it will take to code a bunch of classes. However, this short exercise will provide the basis for the entire project, whether small or large and be a great friend when communicating to anyone on your team or even your client. I call this the Project Brief. If you find yourself going beyond a single page, then you must decompose the sections and summarize your findings so there is a complete and clear picture of the project you are working on in a relatively short statement. Here is a great quote from the PMBOK (Project Management Body of Knowledge) relative to what a project is;   A project is a temporary endeavor undertaken to create a unique product, service or result. With this in mind, the project brief should encompass the entirety (objective) of the endeavor in its explanation and what it will take (goals) to create the product, service or result (deliverables). Normally the process of identifying the project objective is done during the first stage of a project called the Project Kickoff, but you can perform this very important step anytime to help you get a bearing. There are many more parts to helping a project stay on course, but this is usually the foundation where it can be grounded on. Through a series of 3 exercises, you should be able to come up with the objective, goals and deliverables on your project. Follow these steps, and in no time (about &frac12; hour), you will have the foundation of your project plan. (See examples below) Exercise 1 – Objectives Begin with the end in mind. Think about your project in business terms with a couple things to help you understand the objective; Reference the business benefit in terms of cost, speed and / or quality, Provide a higher level of what the outcome will look like (future sense) It should be non-measurable, that’s what the goals are all about The output should be a single paragraph with three sentences and take 10 minutes to write. *Typically, agreement must be reached on the objectives of the project before you would proceed to the next steps of the project. Exercise 2 – Goals A project goal is a statement that answers questions about who, what, why, where and when. A good project goal statement; Answers the five “W” questions for the project Is measurable in each of its parts Is published and agreed on by all the owners This helps the Project Manager receive confirmation on defining the project target. Using the established project objective done in the first exercise, think about the things it will take to get the job done. Think about tangible activities which are the top level tasks in a typical Work Breakdown Structure (WBS). The overall goal statement plus all the deliverables (next exercise) can be seen as the project team’s contract with the project owners. Write 3 - 5 goals in about 10 minutes. You should not write the words “Who, what, why, where and when, but merely be able to answer the questions when you read a goal. Exercise 3 – Deliverables Every project creates some type of output and these outputs are called deliverables. There are two classes of deliverables; Internal – produced for project team members to meet their goals External – produced for project owners to meet their expectations The list you enter here provides a checklist for the team’s delivery and/or is a statement of all the expectations of the project owners. Here are some typical project deliverables; Product and product documentation End product/system Requirements/feature documents Installation guides Demo/prototype System design documents User guides/help files Plans Project plan Training plan Conversion/installation/delivery plan Test plans Documentation plan Communication plan Reports and general documentation Progress reports System acceptance tests Outstanding bug list Procedures Risk and issue logs Project history Deliverables should go with each of the goals. Have 3-5 deliverables for each goal. When you are done, you will have established a great foundation for the clarity of your project. This exercise can take some time, but with practice, you should be able to whip this one out in 10 minutes as well, especially if you are intimate with an ongoing project. Samples  Objective [Client] is implementing a series of MOSS sites to support external public (Internet), internal employee (Intranet) and an external secure (password protected Internet) applications. This project will focus on the public-facing web site and will provide [Client] with architectural recommendations based on the current design being done by their design partner [Partner] and the internal Content Team. In addition, it will provide [Client] with a development plan and confidence they need to deploy a world class public Internet website. Goals 1.  [Consultant] will provide technical guidance and set project team expectations for the implementation of the MOSS Internet site based on provided features/functions within three weeks. 2.  [Consultant] will understand phase 2 secure password-protected Internet site design and provide recommendations.   Deliverables 1.1  Public Internet (unsecure) Architectural Recommendation Plan 1.2  Physical Site construction Work Breakdown Structure and plan (Time, cost and resources needed) 2.1  Two Factor authentication recommendation document   Objective [Client] is currently using an application developed by [Consultant] many years ago called "XXX". This application, although functional, does not meet their new updated business requirements and contains a few defects which [Client] has developed work-around processes. [Client] would like to have a "new and improved" system to support their membership management needs by expanding membership and subscription capabilities, provide accounting integration with internal (GL) and external (VeriSign) systems, and implement hooks to the current CRM solution. This effort will take place through a series of phases, beginning with envisioning. Goals 1. Through discussions with users, [Consultant] will discover current issues/bugs which need to be resolved which must meet the current functionality requirements within three weeks. 2. [Consultant] will gather requirements from the users about what is "needed" vs. "what they have" for enhancements and provide a high level document supporting their needs. 3. [Consultant] will meet with the team members through a series of meetings and help define the overall project plan to deliver a new and improved solution. Deliverables 1.1 Prioritized list of Current application issues/bugs that need to be resolved 1.2 Provide a resolution plan on the issues/bugs identified in the current application 1.3 Risk Assessment Document 2.1 Deliver a Requirements Document showing high-level [Client] needs for the new XXX application. · New feature functionality not in the application today · Existing functionality that will remain in the new functionality 2.2 Reporting Requirements Document 3.1 A Project Plan showing the deliverables and cost for the next (second) phase of this project. 3.2 A Statement of Work for the next (second) phase of this project. 3.3 An Estimate of any work that would need to follow the second phase.

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• C# Performance Pitfall – Interop Scenarios Change the Rules

  - by Reed

  C# and .NET, overall, really do have fantastic performance in my opinion.  That being said, the performance characteristics dramatically differ from native programming, and take some relearning if you’re used to doing performance optimization in most other languages, especially C, C++, and similar.  However, there are times when revisiting tricks learned in native code play a critical role in performance optimization in C#. I recently ran across a nasty scenario that illustrated to me how dangerous following any fixed rules for optimization can be… The rules in C# when optimizing code are very different than C or C++.  Often, they’re exactly backwards.  For example, in C and C++, lifting a variable out of loops in order to avoid memory allocations often can have huge advantages.  If some function within a call graph is allocating memory dynamically, and that gets called in a loop, it can dramatically slow down a routine. This can be a tricky bottleneck to track down, even with a profiler.  Looking at the memory allocation graph is usually the key for spotting this routine, as it’s often “hidden” deep in call graph.  For example, while optimizing some of my scientific routines, I ran into a situation where I had a loop similar to: for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i]); } .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } This loop was at a fairly high level in the call graph, and often could take many hours to complete, depending on the input data.  As such, any performance optimization we could achieve would be greatly appreciated by our users. After a fair bit of profiling, I noticed that a couple of function calls down the call graph (inside of ProcessElement), there was some code that effectively was doing: // Allocate some data required DataStructure* data = new DataStructure(num); // Call into a subroutine that passed around and manipulated this data highly CallSubroutine(data); // Read and use some values from here double values = data->Foo; // Cleanup delete data; // ... return bar; Normally, if “DataStructure” was a simple data type, I could just allocate it on the stack.  However, it’s constructor, internally, allocated it’s own memory using new, so this wouldn’t eliminate the problem.  In this case, however, I could change the call signatures to allow the pointer to the data structure to be passed into ProcessElement and through the call graph, allowing the inner routine to reuse the same “data” memory instead of allocating.  At the highest level, my code effectively changed to something like: DataStructure* data = new DataStructure(numberToProcess); for (i=0; i<numberToProcess; ++i) { // Do some work ProcessElement(element[i], data); } delete data; Granted, this dramatically reduced the maintainability of the code, so it wasn’t something I wanted to do unless there was a significant benefit.  In this case, after profiling the new version, I found that it increased the overall performance dramatically – my main test case went from 35 minutes runtime down to 21 minutes.  This was such a significant improvement, I felt it was worth the reduction in maintainability. In C and C++, it’s generally a good idea (for performance) to: Reduce the number of memory allocations as much as possible, Use fewer, larger memory allocations instead of many smaller ones, and Allocate as high up the call stack as possible, and reuse memory I’ve seen many people try to make similar optimizations in C# code.  For good or bad, this is typically not a good idea.  The garbage collector in .NET completely changes the rules here. In C#, reallocating memory in a loop is not always a bad idea.  In this scenario, for example, I may have been much better off leaving the original code alone.  The reason for this is the garbage collector.  The GC in .NET is incredibly effective, and leaving the allocation deep inside the call stack has some huge advantages.  First and foremost, it tends to make the code more maintainable – passing around object references tends to couple the methods together more than necessary, and overall increase the complexity of the code.  This is something that should be avoided unless there is a significant reason.  Second, (unlike C and C++) memory allocation of a single object in C# is normally cheap and fast.  Finally, and most critically, there is a large advantage to having short lived objects.  If you lift a variable out of the loop and reuse the memory, its much more likely that object will get promoted to Gen1 (or worse, Gen2).  This can cause expensive compaction operations to be required, and also lead to (at least temporary) memory fragmentation as well as more costly collections later. As such, I’ve found that it’s often (though not always) faster to leave memory allocations where you’d naturally place them – deep inside of the call graph, inside of the loops.  This causes the objects to stay very short lived, which in turn increases the efficiency of the garbage collector, and can dramatically improve the overall performance of the routine as a whole. In C#, I tend to: Keep variable declarations in the tightest scope possible Declare and allocate objects at usage While this tends to cause some of the same goals (reducing unnecessary allocations, etc), the goal here is a bit different – it’s about keeping the objects rooted for as little time as possible in order to (attempt) to keep them completely in Gen0, or worst case, Gen1.  It also has the huge advantage of keeping the code very maintainable – objects are used and “released” as soon as possible, which keeps the code very clean.  It does, however, often have the side effect of causing more allocations to occur, but keeping the objects rooted for a much shorter time. Now – nowhere here am I suggesting that these rules are hard, fast rules that are always true.  That being said, my time spent optimizing over the years encourages me to naturally write code that follows the above guidelines, then profile and adjust as necessary.  In my current project, however, I ran across one of those nasty little pitfalls that’s something to keep in mind – interop changes the rules. In this case, I was dealing with an API that, internally, used some COM objects.  In this case, these COM objects were leading to native allocations (most likely C++) occurring in a loop deep in my call graph.  Even though I was writing nice, clean managed code, the normal managed code rules for performance no longer apply.  After profiling to find the bottleneck in my code, I realized that my inner loop, a innocuous looking block of C# code, was effectively causing a set of native memory allocations in every iteration.  This required going back to a “native programming” mindset for optimization.  Lifting these variables and reusing them took a 1:10 routine down to 0:20 – again, a very worthwhile improvement. Overall, the lessons here are: Always profile if you suspect a performance problem – don’t assume any rule is correct, or any code is efficient just because it looks like it should be Remember to check memory allocations when profiling, not just CPU cycles Interop scenarios often cause managed code to act very differently than “normal” managed code. Native code can be hidden very cleverly inside of managed wrappers

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• JSP Precompilation for ADF Applications

  - by Duncan Mills

  A question that comes up from time to time, particularly in relation to build automation, is how to best pre-compile the .jspx and .jsff files in an ADF application. Thus ensuring that the app is ready to run as soon as it's installed into WebLogic. In the normal run of things, the first poor soul to hit a page pays the price and has to wait a little whilst the JSP is compiled into a servlet. Everyone else subsequently gets a free lunch. So it's a reasonable thing to want to do... Let Me List the Ways So forth to Google (other search engines are available)... which lead me to a fairly old article on WLDJ - Removing Performance Bottlenecks Through JSP Precompilation. Technololgy wise, it's somewhat out of date, but the one good point that it made is that it's really not very useful to try and use the precompile option in the weblogic.xml file. That's a really good observation - particularly if you're trying to integrate a pre-compile step into a Hudson Continuous Integration process. That same article mentioned an alternative approach for programmatic pre-compilation using weblogic.jspc. This seemed like a much more useful approach for a CI environment. However, weblogic.jspc is now obsoleted by weblogic.appc so we'll use that instead.  Thanks to Steve for the pointer there. And So To APPC APPC has documentation - always a great place to start, and supports usage both from Ant via the wlappc task and from the command line using the weblogic.appc command. In my testing I took the latter approach. Usage, as the documentation will show you, is superficially pretty simple.  The nice thing here, is that you can pass an existing EAR file (generated of course using OJDeploy) and that EAR will be updated in place with the freshly compiled servlet classes created from the JSPs. Appc takes care of all the unpacking, compiling and re-packing of the EAR for you. Neat.  So we're done right...? Not quite. The Devil is in the Detail  OK so I'm being overly dramatic but it's not all plain sailing, so here's a short guide to using weblogic.appc to compile a simple ADF application without pain.  Information You'll Need The following is based on the assumption that you have a stand-alone WLS install with the Application Development  Runtime installed and a suitable ADF enabled domain created. This could of course all be run off of a JDeveloper install as well 1. Your Weblogic home directory. Everything you need is relative to this so make a note.  In my case it's c:\builds\wls_ps4. 2. Next deploy your EAR as normal and have a peek inside it using your favourite zip management tool. First of all look at the weblogic-application.xml inside the EAR /META-INF directory. Have a look for any library references. Something like this: <library-ref>    <library-name>adf.oracle.domain</library-name> </library-ref>   Make a note of the library ref (adf.oracle.domain in this case) , you'll need that in a second. 3. Next open the nested WAR file within the EAR and then have a peek inside the weblogic.xml file in the /WEB-INF directory. Again  make a note of the library references. 4. Now start the WebLogic as per normal and run the WebLogic console app (e.g. http://localhost:7001/console). In the Domain Structure navigator, select Deployments. 5. For each of the libraries you noted down drill into the library definition and make a note of the .war, .ear or .jar that defines the library. For example, in my case adf.oracle.domain maps to "C:\ builds\ WLS_PS4\ oracle_common\ modules\ oracle. adf. model_11. 1. 1\ adf. oracle. domain. ear". Note the extra spaces that are salted throughout this string as it is displayed in the console - just to make it annoying, you'll have to strip these out. 6. Finally you'll need the location of the adfsharebean.jar. We need to pass this on the classpath for APPC so that the ADFConfigLifeCycleCallBack listener can be found. In a more complex app of your own you may need additional classpath entries as well.  Now we're ready to go, and it's a simple matter of applying the information we have gathered into the relevant command line arguments for the utility A Simple CMD File to Run APPC  Here's the stub .cmd file I'm using on Windows to run this. @echo offREM Stub weblogic.appc Runner setlocal set WLS_HOME=C:\builds\WLS_PS4 set ADF_LIB_ROOT=%WLS_HOME%\oracle_common\modulesset COMMON_LIB_ROOT=%WLS_HOME%\wlserver_10.3\common\deployable-libraries set ADF_WEBAPP=%ADF_LIB_ROOT%\oracle.adf.view_11.1.1\adf.oracle.domain.webapp.war set ADF_DOMAIN=%ADF_LIB_ROOT%\oracle.adf.model_11.1.1\adf.oracle.domain.ear set JSTL=%COMMON_LIB_ROOT%\jstl-1.2.war set JSF=%COMMON_LIB_ROOT%\jsf-1.2.war set ADF_SHARE=%ADF_LIB_ROOT%\oracle.adf.share_11.1.1\adfsharembean.jar REM Set up the WebLogic Environment so appc can be found call %WLS_HOME%\wlserver_10.3\server\bin\setWLSEnv.cmd CLS REM Now compile away!java weblogic.appc -verbose -library %ADF_WEBAPP%,%ADF_DOMAIN%,%JSTL%,%JSF% -classpath %ADF_SHARE% %1 endlocal Running the above on a target ADF .ear  file will zip through and create all of the relevant compiled classes inside your nested .war file in the \WEB-INF\classes\jsp_servlet\ directory (but don't take my word for it, run it and take a look!) And So... In the immortal words of  the Pet Shop Boys, Was It Worth It? Well, here's where you'll have to do your own testing. In  my case here, with a simple ADF application, pre-compilation shaved an non-scientific "3 Elephants" off of the initial page load time for the first access of each page. That's a pretty significant payback for such a simple step to add into your CI process, so why not give it a go.

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• CodePlex Daily Summary for Monday, May 26, 2014

  CodePlex Daily Summary for Monday, May 26, 2014Popular ReleasesClosedXML - The easy way to OpenXML: ClosedXML 0.71.1: More performance improvements. It's faster and consumes less memory.Role Based Views in Microsoft Dynamics CRM 2011: Role Based Views in CRM 2011 and 2013 - 1.1.0.0: Issues fixed in this build: 1. Works for CRM 2013 2. Lookup view not getting blockedSimCityPak: SimCityPak 0.3.1.0: Main New Features: Fixed Importing of Instance Names (get rid of the Dutch translations) Added advanced editor for Decal Dictionaries Added possibility to import .PNG to generate new decals Added advanced editor for Path display entriesSimple Connect To Db: SimpleConnectToDb_v1: SimpleConnectToDb_v1CRM 2011 / CRM 2013 Form Helper: v2014.05.25: v2014.05.25 Added PhoneFormat & PhoneFormatAreaCode v2014.05.24 Initial ReleaseCreate Word documents without MS Word: Release 3.0: Add support for Sections, Sections Headers and Footers and right to left languages.Corporate News App for SharePoint 2013: CorporateNewsApp v1.6.2.0: Important note This version contains a major bug fix about the generic error "Request failed. Unexpected response data from server null" This error occurs on SharePoint Online only, following an update of the Javascript API after May 2014. If you have installed this application manually in your applications company catalog, you can download the CorporateNewsApp.app file in the zip archive and update it manually. If you have installed this application directly from the SharePoint Store, it ...DevOS: DevOS: Plugin-system added Including:DevOS.exe DevOS API.dll Files must be in the some folderTiny Deduplicator: Tiny Deduplicator 1.0.1.0: Increased version number to 1.0.1.0 Moved all options to a separate 'Options' dialog window. Allows the user to specify a selection strategy which will help when dealing with large numbers of duplicate files. Available options are "None," "Keep First," and "Keep Last"C64 Studio: 3.5: Add: BASIC renumber function Add: !PET pseudo op Add: elseif for !if, } else { pseudo op Add: !TRACE pseudo op Add: Watches are saved/restored with a solution Add: Ctrl-A works now in export assembly controls Add: Preliminary graphic import dialog (not fully functional yet) Add: range and block selection in sprite/charset editor (Shift-Click = range, Alt-Click = block) Fix: Expression evaluator could miscalculate when both division and multiplication were in an expression without parenthesisSEToolbox: SEToolbox 01.031.009 Release 1: Added mirroring of ConveyorTubeCurved. Updated Ship cube rotation to rotate ship back to original location (cubes are reoriented but ship appears no different to outsider), and to rotate Grouped items. Repair now fixes the loss of Grouped controls due to changes in Space Engineers 01.030. Added export asteroids. Rejoin ships will merge grouping and conveyor systems (even though broken ships currently only maintain the Grouping on one part of the ship). Installation of this version wi...Player Framework by Microsoft: Player Framework for Windows and WP v2.0: Support for new Universal and Windows Phone 8.1 projects for both Xaml and JavaScript projects. See a detailed list of improvements, breaking changes and a general overview of version 2 ADDITIONAL DOWNLOADSSmooth Streaming Client SDK for Windows 8 Applications Smooth Streaming Client SDK for Windows 8.1 Applications Smooth Streaming Client SDK for Windows Phone 8.1 Applications Microsoft PlayReady Client SDK for Windows 8 Applications Microsoft PlayReady Client SDK for Windows 8.1 Applicat...TerraMap (Terraria World Map Viewer): TerraMap 1.0.6: Added support for the new Terraria v1.2.4 update. New items, walls, and tiles Added the ability to select multiple highlighted block types. Added a dynamic, interactive highlight opacity slider, making it easier to find highlighted tiles with dark colors (and fixed blurriness from 1.0.5 alpha). Added ability to find Enchanted Swords (in the stone) and Water Bolt books Fixed Issue 35206: Hightlight/Find doesn't work for Demon Altars Fixed finding Demon Hearts/Shadow Orbs Fixed inst...DotNet.Highcharts: DotNet.Highcharts 4.0 with Examples: DotNet.Highcharts 4.0 Tested and adapted to the latest version of Highcharts 4.0.1 Added new chart type: Heatmap Added new type PointPlacement which represents enumeration or number for the padding of the X axis. Changed target framework from .NET Framework 4 to .NET Framework 4.5. Closed issues: 974: Add 'overflow' property to PlotOptionsColumnDataLabels class 997: Split container from JS 1006: Series/Categories with numeric names don't render DotNet.Highcharts.Samples Updated s...ConEmu - Windows console with tabs: ConEmu 140523 [Alpha]: ConEmu - developer build x86 and x64 versions. Written in C++, no additional packages required. Run "ConEmu.exe" or "ConEmu64.exe". Some useful information you may found: http://superuser.com/questions/tagged/conemu http://code.google.com/p/conemu-maximus5/wiki/ConEmuFAQ http://code.google.com/p/conemu-maximus5/wiki/TableOfContents If you want to use ConEmu in portable mode, just create empty "ConEmu.xml" file near to "ConEmu.exe" Aspose for Apache POI: Missing Features of Apache POI SL - v 1.1: Release contain the Missing Features in Apache POI SL SDK in Comparison with Aspose.Slides for dealing with Microsoft Power Point. What's New ?Following Examples: Managing Slide Transitions Manage Smart Art Adding Media Player Adding Audio Frame to Slide Feedback and Suggestions Many more examples are yet to come here. Keep visiting us. Raise your queries and suggest more examples via Aspose Forums or via this social coding site.PowerShell App Deployment Toolkit: PowerShell App Deployment Toolkit v3.1.3: Added CompressLogs option to the config file. Each Install / Uninstall creates a timestamped zip file with all MSI and PSAppDeployToolkit logs contained within Added variable expansion to all paths in the configuration file Added documentation for each of the Toolkit internal variables that can be used Changed Install-MSUpdates to continue if any errors are encountered when installing updates Implement /Force parameter on Update-GroupPolicy (ensure that any logoff message is ignored) ...WordMat: WordMat v. 1.07: A quick fix because scientific notation was broken in v. 1.06 read more at http://wordmat.blogspot.com????: 《????》: 《????》（c???）??“????”???????，???????????????C?????????。???????,???????????????????????. ??????????????????????????????????；????????????????????????????。Mini SQL Query: Mini SQL Query (1.0.72.457): Apologies for the previous update! FK issue fixed and also a template data cache issue.New ProjectsASP.Net MCV4 Simplified Code Samples: This project intended to simplify the same. In this project each task is implemented with minimum lines of code to reduces complicity.Calvin: net???CodeLatino by Latinosoft: A Modified version for codeShow -- Probably taking more than a month.freeasyBackup: A free and easy to use Backup Tool for everyone. Without any cloud restrictions. freeasyExplorer: A free and easy to use File Explorer for everyone.openPDFspeedreader: #spritz #pdfreader #speedreader PDF Editor to Edit PDF Files in your ASP.NET Applications: This sample application allows the users to edit PDF files online using Aspose.Pdf for .NET.SharePoint World Cup 2013: world cup 2014SSAS Long Running Query Performance Helper: This utility helps investigate long running multidimensional or mining queries in discovery, de-parameterization and re-parameterization back to source format.

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• Bazaar newbie question about repository structures

  - by esc1729

  I want to use Bazaar on Windows XP for web-development and related tasks. Most of the files are edited locally and then transferred via FTP to the server. Just now the repository sits on my local workstation. Later on it should be shared locally with some co-workers. Perhaps we will use a local Linux server as a centralized repository, but this structure is not decided for now. But first I need to understand the impacts of the different repository setups, which I do not at all. Using Bazaar-Explorer on Windows XP I’ve created a ‘shared tree repository’ from the option list of the init-dialogue in some location dev-filter/. Bazaar Explorer tells me: Created repository with treeless branches at F:/bzr.local/dev-filter Created branch at F:/bzr.local/dev-filter/trunk Created working tree at F:/bzr.local/dev-filter/work OK so far. Now I move a bunch of files into the work directory and add and commit them as Rev 1 ‘Start Revision’. Then I work on some of these files and commit them again as Rev 2. Here my confusion starts. Shouldn’t both revisions go into the trunk? The trunk is still empty, beside the .bzr directory which only holds some management information. If I delete my working directory, which I have tried during these first experiments, everything is gone. There’s obviously no hidden storage of those files. OK. Perhaps I need to push it into the trunk? This does not work either. Entering the work/ directory and initializing the ‘push’ to the trunk, Bazaar-Explorer tells me No new revisions to push. So what? This looks like a severe conceptual misunderstanding about what should happen on my side. Edit, 2010-02-03: Some conclusions What I learned meanwhile is this: I think I should switch to the command line until I really understand what’s going on, at least for creating the repositories and branches. Bazaar Explorer introduces a new level of abstraction which I only can handle if I understand the level beneath One of the secrets of working with Bazaar at least for me is to understand those .bzr directories, their particular properties and states when created with ‘bzr init’, ‘bzr init-repository’, ‘bzr branch’ etc. in all their variants and how they are plumped together. While there’s a whole chapter of ‘Organizing your workspace’ in the Bazaar User Guide, it’s more or less workflow oriented. The manual contains a lot of directory structures for the given examples. What I would prefer beside this and have not (or only rudimentary) found so far is some graphical representation of those ‘Lego like’ .bzr building blocks which create the linking of all the parts. So I started to invent some simple notation while working through the examples and looking into the .bzr directories to document what information is stored there, where does it come from, how and to what is it linked, is it complete or shared, etc. Erich Schreiber

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• ASP MVC 2: Error with dropdownlist on POST

  - by wh0emPah

  Okay i'm new to asp mvc2 and i'm experiencing some problems with the htmlhelper called Html.dropdownlistfor(); I want to present the user a list of days in the week. And i want the selected item to be bound to my model. I have created this little class to generate a list of days + a short notation which i will use to store it in the database. public static class days { public static List<Day> getDayList() { List<Day> daylist = new List<Day>(); daylist.Add(new Day("Monday", "MO")); daylist.Add(new Day("Tuesday", "TU")); // I left the other days out return daylist; } public class Dag{ public string DayName{ get; set; } public string DayShortName { get; set; } public Dag(string name, string shortname) { this.DayName= name; this.DayShortName = shortname; } } } I really have now idea if this is the correct way to do it Then i putted this in my controller: SelectList _list = new SelectList(Days.getDayList(), "DayShortName", "DayName"); ViewData["days"] = _list; return View(""); I have this line in my model public string ChosenDay { get; set; } And this in my view to display the list: <div class="editor-field"> <%: Html.DropDownListFor(model => model.ChosenDay, ViewData["days"] as SelectList, "--choose Day--")%> </div> Now this all works perfect. On the first visit, But then when i'm doing a [HttpPost] Which looks like the following: [HttpPost] public ActionResult Registreer(EventRegistreerViewModel model) { // I removed some unrelated code here // The code below executes when modelstate.isvalid == false SelectList _list = new SelectList(Days.getDayList(), "DayShortName", "DayName"); ViewData["days"] = _list; return View(model); } Then i will have the following exception thrown: The ViewData item that has the key 'ChosenDay' is of type 'System.String' but must be of type 'IEnumerable<SelectListItem>'. This errors gets thrown at the line in my view where i display the dropdown list. I really have no idea how to solve this and tried several solutions i found online. but none of them really worked. Ty in advance!

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• How to find minimum of nonlinear, multivariate function using Newton's method (code not linear algeb

  - by Norman Ramsey

  I'm trying to do some parameter estimation and want to choose parameter estimates that minimize the square error in a predicted equation over about 30 variables. If the equation were linear, I would just compute the 30 partial derivatives, set them all to zero, and use a linear-equation solver. But unfortunately the equation is nonlinear and so are its derivatives. If the equation were over a single variable, I would just use Newton's method (also known as Newton-Raphson). The Web is rich in examples and code to implement Newton's method for functions of a single variable. Given that I have about 30 variables, how can I program a numeric solution to this problem using Newton's method? I have the equation in closed form and can compute the first and second derivatives, but I don't know quite how to proceed from there. I have found a large number of treatments on the web, but they quickly get into heavy matrix notation. I've found something moderately helpful on Wikipedia, but I'm having trouble translating it into code. Where I'm worried about breaking down is in the matrix algebra and matrix inversions. I can invert a matrix with a linear-equation solver but I'm worried about getting the right rows and columns, avoiding transposition errors, and so on. To be quite concrete: I want to work with tables mapping variables to their values. I can write a function of such a table that returns the square error given such a table as argument. I can also create functions that return a partial derivative with respect to any given variable. I have a reasonable starting estimate for the values in the table, so I'm not worried about convergence. I'm not sure how to write the loop that uses an estimate (table of value for each variable), the function, and a table of partial-derivative functions to produce a new estimate. That last is what I'd like help with. Any direct help or pointers to good sources will be warmly appreciated. Edit: Since I have the first and second derivatives in closed form, I would like to take advantage of them and avoid more slowly converging methods like simplex searches.

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• Fixed point math in c#?

  - by x4000

  Hi there, I was wondering if anyone here knows of any good resources for fixed point math in c#? I've seen things like this (http://2ddev.72dpiarmy.com/viewtopic.php?id=156) and this (http://stackoverflow.com/questions/79677/whats-the-best-way-to-do-fixed-point-math), and a number of discussions about whether decimal is really fixed point or actually floating point (update: responders have confirmed that it's definitely floating point), but I haven't seen a solid C# library for things like calculating cosine and sine. My needs are simple -- I need the basic operators, plus cosine, sine, arctan2, PI... I think that's about it. Maybe sqrt. I'm programming a 2D RTS game, which I have largely working, but the unit movement when using floating-point math (doubles) has very small inaccuracies over time (10-30 minutes) across multiple machines, leading to desyncs. This is presently only between a 32 bit OS and a 64 bit OS, all the 32 bit machines seem to stay in sync without issue, which is what makes me think this is a floating point issue. I was aware from this as a possible issue from the outset, and so have limited my use of non-integer position math as much as possible, but for smooth diagonal movement at varying speeds I'm calculating the angle between points in radians, then getting the x and y components of movement with sin and cos. That's the main issue. I'm also doing some calculations for line segment intersections, line-circle intersections, circle-rect intersections, etc, that also probably need to move from floating-point to fixed-point to avoid cross-machine issues. If there's something open source in Java or VB or another comparable language, I could probably convert the code for my uses. The main priority for me is accuracy, although I'd like as little speed loss over present performance as possible. This whole fixed point math thing is very new to me, and I'm surprised by how little practical information on it there is on google -- most stuff seems to be either theory or dense C++ header files. Anything you could do to point me in the right direction is much appreciated; if I can get this working, I plan to open-source the math functions I put together so that there will be a resource for other C# programmers out there. UPDATE: I could definitely make a cosine/sine lookup table work for my purposes, but I don't think that would work for arctan2, since I'd need to generate a table with about 64,000x64,000 entries (yikes). If you know any programmatic explanations of efficient ways to calculate things like arctan2, that would be awesome. My math background is all right, but the advanced formulas and traditional math notation are very difficult for me to translate into code.

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• Code Golf: Evaluating Mathematical Expressions

  - by Noldorin

  Challenge Here is the challenge (of my own invention, though I wouldn't be surprised if it has previously appeared elsewhere on the web). Write a function that takes a single argument that is a string representation of a simple mathematical expression and evaluates it as a floating point value. A "simple expression" may include any of the following: positive or negative decimal numbers, +, -, *, /, (, ). Expressions use (normal) infix notation. Operators should be evaluated in the order they appear, i.e. not as in BODMAS, though brackets should be correctly observed, of course. The function should return the correct result for any possible expression of this form. However, the function does not have to handle malformed expressions (i.e. ones with bad syntax). Examples of expressions: 1 + 3 / -8 = -0.5 (No BODMAS) 2*3*4*5+99 = 219 4 * (9 - 4) / (2 * 6 - 2) + 8 = 10 1 + ((123 * 3 - 69) / 100) = 4 2.45/8.5*9.27+(5*0.0023) = 2.68... Rules I anticipate some form of "cheating"/craftiness here, so please let me forewarn against it! By cheating, I refer to the use of the eval or equivalent function in dynamic languages such as JavaScript or PHP, or equally compiling and executing code on the fly. (I think my specification of "no BODMAS" has pretty much guaranteed this however.) Apart from that, there are no restrictions. I anticipate a few Regex solutions here, but it would be nice to see more than just that. Now, I'm mainly interested in a C#/.NET solution here, but any other language would be perfectly acceptable too (in particular, F# and Python for the functional/mixed approaches). I haven't yet decided whether I'm going to accept the shortest or most ingenious solution (at least for the language) as the answer, but I would welcome any form of solution in any language, except what I've just prohibited above! My Solution I've now posted my C# solution here (403 chars). Update: My new solution has beaten the old one significantly at 294 chars, with the help of a bit of lovely regex! I suspected that this will get easily beaten by some of the languages out there with lighter syntax (particularly the funcional/dynamic ones), and have been proved right, but I'd be curious if someone could beat this in C# still. Update I've seen some very crafty solutions already. Thanks to everyone who has posted one. Although I haven't tested any of them yet, I'm going to trust people and assume they at least work with all of the given examples. Just for the note, re-entrancy (i.e. thread-safety) is not a requirement for the function, though it is a bonus. Format Please post all answers in the following format for the purpose of easy comparison: Language Number of characters: ??? Fully obfuscated function: (code here) Clear/semi-obfuscated function: (code here) Any notes on the algorithm/clever shortcuts it takes.

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• Scared of Calculus - Required to pass Differential Calculus as part of my Computer science major

  - by ke3pup

  Hi guys I'm finishing my Computer science degree in university but my fear of maths (lack of background knowledge) made me to leave all my maths units til' the very end which is now. i either take them on and pass or have to give up. I've passed all my programming units easily but knowing my poor maths skills won't do i've been staying clear of the maths units. I have to pass Differential Calculus and Linear Algebra first. With a help of book named "Linear Algebra: A Modern Introduction" i'm finding myself on track and i think i can pass the Linear Algebra unit. But with differential calculus i can't find a book to help me. They're either too advanced or just too simple for what i have to learn. The things i'm required to know for this units are: Set notation, the real number line, Complex numbers in cartesian form. Complex plane, modulus. Complex numbers in polar form. De Moivre’s Theorem. Complex powers and nth roots. Definition of ei? and ez for z complex. Applications to trigonometry. Revision of domain and range of a function Working in R3. Curves and surfaces. Functions of 2 variables. Level curves.Partial derivatives and tangent planes. The derivative as a difference quotient. Geometric significance of the derivative. Discussion of limit. Higher order partial derivatives. Limits of f(x,y). Continuity. Maxima and minima of f(x,y). The chain rule. Implicit differentiation. Directional derivatives and the gradient. Limit laws, l’Hoˆpital’s rule, composition law. Definition of sinh and cosh and their inverses. Taylor polynomials. The remainder term. Taylor series. Is there a book to help me get on track with the above? Being a student i can't buy too many books hence why i'm looking for a book that covers topics I need to know. The University library has a fairly limited collection which i took as loan but didn't find useful as it was too complex.

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• Turtle Graphics as a Haskell Monad

  - by iliis

  I'm trying to implement turtle graphis in Haskell. The goal is to be able to write a function like this: draw_something = do fordward 100 right 90 forward 100 ... and then have it produce a list of points (maybe with additional properties): > draw_something (0,0) 0 -- start at (0,0) facing east (0 degrees) [(0,0), (0,100), (-100,100), ...] I have all this working in a 'normal' way, but I fail to implement it as a Haskell Monad and use the do-notation. The basic code: data State a = State (a, a) a -- (x,y), angle deriving (Show, Eq) initstate :: State Float initstate = State (0.0,0.0) 0.0 -- constrain angles to 0 to 2*pi fmod :: Float -> Float fmod a | a >= 2*pi = fmod (a-2*pi) | a < 0 = fmod (a+2*pi) | otherwise = a forward :: Float -> State Float -> [State Float] forward d (State (x,y) angle) = [State (x + d * (sin angle), y + d * (cos angle)) angle] right :: Float -> State Float -> [State Float] right d (State pos angle) = [State pos (fmod (angle+d))] bind :: [State a] -> (State a -> [State a]) -> [State a] bind xs f = xs ++ (f (head $ reverse xs)) ret :: State a -> [State a] ret x = [x] With this I can now write > [initstate] `bind` (forward 100) `bind` (right (pi/2)) `bind` (forward 100) [State (0.0,0.0) 0.0,State (0.0,100.0) 0.0,State (0.0,100.0) 1.5707964,State (100.0,99.99999) 1.5707964] And get the expected result. However I fail to implement this as an instance of Monad. instance Monad [State] where ... results in `State' is not applied to enough type arguments Expected kind `*', but `State' has kind `* -> *' In the instance declaration for `Monad [State]' And if I wrap the list in a new object data StateList a = StateList [State a] instance Monad StateList where return x = StateList [x] I get Couldn't match type `a' with `State a' `a' is a rigid type variable bound by the type signature for return :: a -> StateList a at logo.hs:38:9 In the expression: x In the first argument of `StateList', namely `[x]' In the expression: StateList [x] I tried various other versions but I never got it to run as I'd like to. What am I doing wrong? What do I understand incorrectly?

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