Search Results

Search found 61241 results on 2450 pages for 'empty set'.

Page 322/2450 | < Previous Page | 318 319 320 321 322 323 324 325 326 327 328 329  | Next Page >

• Forwarding a subdomain to main domain using Godaddy.

  - by Ryan Hayes

  I have current blog, which was hosted on Tumblr at http://blog.ryanhayes.net. I'm moving it over to http://ryanhayes.net, and have all the 301 redirects set up for the blog entries to map to my new blog, which is hosted using Godaddy (domain included). When I try to set up a subdomain forward, I'm greeted with a nice 403 Forbidden response (as of this writing, you can see it at http://blog.ryanhayes.net. When I try to ping both the subdomain and domain, they point to the same IP address, so I know blog subdomain has at least switched over to point to the same content. I don't really understand why I would get a 403 Forbidden on the same content that I can see perfectly fine via another domain. Currently, I have a CNAME of blog pointing to @, which is how "www" is set up to forward, so I'm assuming it would do the same thing. My question is what is the proper way to set up my DNS to make the blog subdomain forward to my main domain (301) using the GoDaddy DNS manager? Bonus: What is the background on why I am getting a 403 error the current way? Forbidden You don't have permission to access / on this server. Additionally, a 403 Forbidden error was encountered while trying to use an ErrorDocument to handle the request. UPDATE 12/7/2010 Error on site has been fixed, you can no longer view it from my site.

  Read the article

• Enum.HasFlag

  - by Scott Dorman

  An enumerated type, also called an enumeration (or just an enum for short), is simply a way to create a numeric type restricted to a predetermined set of valid values with meaningful names for those values. While most enumerations represent discrete values, or well-known combinations of those values, sometimes you want to combine values in an arbitrary fashion. These enumerations are known as flags enumerations because the values represent flags which can be set or unset. To combine multiple enumeration values, you use the logical OR operator. For example, consider the following: public enum FileAccess { None = 0, Read = 1, Write = 2, }   class Program { static void Main(string[] args) { FileAccess access = FileAccess.Read | FileAccess.Write; Console.WriteLine(access); } } The output of this simple console application is: The value 3 is the numeric value associated with the combination of FileAccess.Read and FileAccess.Write. Clearly, this isn’t the best representation. What you really want is for the output to look like: To achieve this result, you simply add the Flags attribute to the enumeration. The Flags attribute changes how the string representation of the enumeration value is displayed when using the ToString() method. Although the .NET Framework does not require it, enumerations that will be used to represent flags should be decorated with the Flags attribute since it provides a clear indication of intent. One “problem” with Flags enumerations is determining when a particular flag is set. The code to do this isn’t particularly difficult, but unless you use it regularly it can be easy to forget. To test if the access variable has the FileAccess.Read flag set, you would use the following code: (access & FileAccess.Read) == FileAccess.Read Starting with .NET 4, a HasFlag static method has been added to the Enum class which allows you to easily perform these tests: access.HasFlag(FileAccess.Read) This method follows one of the “themes” for the .NET Framework 4, which is to simplify and reduce the amount of boilerplate code like this you must write. Technorati Tags: .NET,C# 4

  Read the article

• Operation MVC

  - by Ken Lovely, MCSE, MCDBA, MCTS

  It was time to create a new site. I figured VS 2010 is out so I should write it using MVC and Entity Framework. I have been very happy with MVC. My boss has had me making an administration web site in MVC2 but using 2008. I think one of the greatest features of MVC is you get to work with root of the app. It is kind of like being an iron worker; you get to work with the metal, mold it from scratch. Getting my articles out of my database and onto web pages was by far easier with MVC than it was with regular ASP.NET. This code is what I use to post the article to that page. It's pretty straightforward. The link in the menu is passes the id which is simply the url to the page. It looks for that url in the database and returns the rest of the article.   DataResults dr = new DataResults(); string title = string.Empty; string article = string.Empty; foreach (var D in dr.ReturnArticle(ViewData["PageName"].ToString())) { title = D.Title; article = D.Article; } public   List<CurrentArticle> ReturnArticle(string id) { var resultlist = new List<CurrentArticle>(); DBDataContext context = new DBDataContext(); var results = from D in context.MyContents where D.MVCURL.Contains(id) select D;foreach (var result in results) { CurrentArticle ca = new CurrentArticle(); ca.Title = result.Title; ca.Article = result.Article; ca.Summary = result.Summary; resultlist.Add(ca); } return resultlist;}

  Read the article

• Ruby on Rails - Belongs_to and Active Admin not creating foreign ID

  - by Milo

  I have the following setup: class Category < ActiveRecord::Base has_many :products end class Product < ActiveRecord::Base belongs_to :category has_attached_file :photo, :styles => { :medium => "300x300>", :thumb => "200x200>" } validates_attachment_content_type :photo, :content_type => /\Aimage\/.*\Z/ end ActiveAdmin.register Product do permit_params :title, :price, :slideshow, :photo, :category form do |f| f.inputs "Product Details" do f.input :title f.input :category f.input :price f.input :slideshow f.input :photo, :required => false, :as => :file end f.actions end show do |ad| attributes_table do row :title row :category row :photo do image_tag(ad.photo.url(:medium)) end end end index do column :id column :title column :category column :price do |product| number_to_currency product.price end actions end class ProductController < ApplicationController def create @product = Product.create(params[:id]) end end Every time I make a product item in activeadmin the category comes up empty. It wont populate the column category_id for the product. It just leaves it empty. What am I doing wrong?

  Read the article

• Oracle Solaris 11 ZFS Lab for Openworld 2012

  - by user12626122

  Preface This is the content from the Oracle Openworld 2012 ZFS lab. It was well attended - the feedback was that it was a little short - thats probably because in writing it I bacame very time-concious after the ASM/ACFS on Solaris extravaganza I ran last year which was almost too long for mortal man to finish in the 1 hour session. Enjoy. Table of Contents Exercise Z.1: ZFS Pools Exercise Z.2: ZFS File Systems Exercise Z.3: ZFS Compression Exercise Z.4: ZFS Deduplication Exercise Z.5: ZFS Encryption Exercise Z.6: Solaris 11 Shadow Migration Introduction This set of exercises is designed to briefly demonstrate new features in Solaris 11 ZFS file system: Deduplication, Encryption and Shadow Migration. Also included is the creation of zpools and zfs file systems - the basic building blocks of the technology, and also Compression which is the compliment of Deduplication. The exercises are just introductions - you are referred to the ZFS Adminstration Manual for further information. From Solaris 11 onward the online manual pages consist of zpool(1M) and zfs(1M) with further feature-specific information in zfs_allow(1M), zfs_encrypt(1M) and zfs_share(1M). The lab is easily carried out in a VirtualBox running Solaris 11 with 6 virtual 3 Gb disks to play with. Exercise Z.1: ZFS Pools Task: You have several disks to use for your new file system. Create a new zpool and a file system within it. Lab: You will check the status of existing zpools, create your own pool and expand it. Your Solaris 11 installation already has a root ZFS pool. It contains the root file system. Check this: root@solaris:~# zpool list NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT rpool 15.9G 6.62G 9.25G 41% 1.00x ONLINE - root@solaris:~# zpool status pool: rpool state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM rpool ONLINE 0 0 0 c3t0d0s0 ONLINE 0 0 0 errors: No known data errors Note the disk device the root pool is on - c3t0d0s0 Now you will create your own ZFS pool. First you will check what disks are available: root@solaris:~# echo | format Searching for disks...done AVAILABLE DISK SELECTIONS: 0. c3t0d0 <ATA-VBOX HARDDISK-1.0 cyl 2085 alt 2 hd 255 sec 63> /pci@0,0/pci8086,2829@d/disk@0,0 1. c3t2d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@2,0 2. c3t3d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@3,0 3. c3t4d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@4,0 4. c3t5d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@5,0 5. c3t6d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@6,0 6. c3t7d0 <ATA-VBOX HARDDISK-1.0 cyl 1534 alt 2 hd 128 sec 32> /pci@0,0/pci8086,2829@d/disk@7,0 Specify disk (enter its number): Specify disk (enter its number): The root disk is numbered 0. The others are free for use. Try creating a simple pool and observe the error message: root@solaris:~# zpool create mypool c3t2d0 c3t3d0 'mypool' successfully created, but with no redundancy; failure of one device will cause loss of the pool So destroy that pool and create a mirrored pool instead: root@solaris:~# zpool destroy mypool root@solaris:~# zpool create mypool mirror c3t2d0 c3t3d0 root@solaris:~# zpool status mypool pool: mypool state: ONLINE scan: none requested config: NAME STATE READ WRITE CKSUM mypool ONLINE 0 0 0 mirror-0 ONLINE 0 0 0 c3t2d0 ONLINE 0 0 0 c3t3d0 ONLINE 0 0 0 errors: No known data errors Back to topExercise Z.2: ZFS File Systems Task: You have to create file systems for later exercises. You can see that when a pool is created, a file system of the same name is created: root@solaris:~# zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 86.5K 2.94G 31K /mypool Create your filesystems and mountpoints as follows: root@solaris:~# zfs create -o mountpoint=/data1 mypool/mydata1 The -o option sets the mount point and automatically creates the necessary directory. root@solaris:~# zfs list mypool/mydata1 NAME USED AVAIL REFER MOUNTPOINT mypool/mydata1 31K 2.94G 31K /data1 Back to top Exercise Z.3: ZFS Compression Task:Try out different forms of compression available in ZFS Lab:Create 2nd filesystem with compression, fill both file systems with the same data, observe results You can see from the zfs(1) manual page that there are several types of compression available to you, set with the property=value syntax: compression=on | off | lzjb | gzip | gzip-N | zle Controls the compression algorithm used for this dataset. The lzjb compression algorithm is optimized for performance while providing decent data compression. Setting compression to on uses the lzjb compression algorithm. The gzip compression algorithm uses the same compression as the gzip(1) command. You can specify the gzip level by using the value gzip-N where N is an integer from 1 (fastest) to 9 (best compression ratio). Currently, gzip is equivalent to gzip-6 (which is also the default for gzip(1)). Create a second filesystem with compression turned on. Note how you set and get your values separately: root@solaris:~# zfs create -o mountpoint=/data2 mypool/mydata2 root@solaris:~# zfs set compression=gzip-9 mypool/mydata2 root@solaris:~# zfs get compression mypool/mydata1 NAME PROPERTY VALUE SOURCE mypool/mydata1 compression off default root@solaris:~# zfs get compression mypool/mydata2 NAME PROPERTY VALUE SOURCE mypool/mydata2 compression gzip-9 local Now you can copy the contents of /usr/lib into both your normal and compressing filesystem and observe the results. Don't forget the dot or period (".") in the find(1) command below: root@solaris:~# cd /usr/lib root@solaris:/usr/lib# find . -print | cpio -pdv /data1 root@solaris:/usr/lib# find . -print | cpio -pdv /data2 The copy into the compressing file system takes longer - as it has to perform the compression but the results show the effect: root@solaris:/usr/lib# zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 1.35G 1.59G 31K /mypool mypool/mydata1 1.01G 1.59G 1.01G /data1 mypool/mydata2 341M 1.59G 341M /data2 Note that the available space in the pool is shared amongst the file systems. This behavior can be modified using quotas and reservations which are not covered in this lab but are covered extensively in the ZFS Administrators Guide. Back to top Exercise Z.4: ZFS Deduplication The deduplication property is used to remove redundant data from a ZFS file system. With the property enabled duplicate data blocks are removed synchronously. The result is that only unique data is stored and common componenents are shared. Task:See how to implement deduplication and its effects Lab: You will create a ZFS file system with deduplication turned on and see if it reduces the amount of physical storage needed when we again fill it with a copy of /usr/lib. root@solaris:/usr/lib# zfs destroy mypool/mydata2 root@solaris:/usr/lib# zfs set dedup=on mypool/mydata1 root@solaris:/usr/lib# rm -rf /data1/* root@solaris:/usr/lib# mkdir /data1/2nd-copy root@solaris:/usr/lib# zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 1.02M 2.94G 31K /mypool mypool/mydata1 43K 2.94G 43K /data1 root@solaris:/usr/lib# find . -print | cpio -pd /data1 2142768 blocks root@solaris:/usr/lib# zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 1.02G 1.99G 31K /mypool mypool/mydata1 1.01G 1.99G 1.01G /data1 root@solaris:/usr/lib# find . -print | cpio -pd /data1/2nd-copy 2142768 blocks root@solaris:/usr/lib#zfs list NAME USED AVAIL REFER MOUNTPOINT mypool 1.99G 1.96G 31K /mypool mypool/mydata1 1.98G 1.96G 1.98G /data1 You could go on creating copies for quite a while...but you get the idea. Note that deduplication and compression can be combined: the compression acts on metadata. Deduplication works across file systems in a pool and there is a zpool-wide property dedupratio: root@solaris:/usr/lib# zpool get dedupratio mypool NAME PROPERTY VALUE SOURCE mypool dedupratio 4.30x - Deduplication can also be checked using "zpool list": root@solaris:/usr/lib# zpool list NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT mypool 2.98G 1001M 2.01G 32% 4.30x ONLINE - rpool 15.9G 6.66G 9.21G 41% 1.00x ONLINE - Before moving on to the next topic, destroy that dataset and free up some space: root@solaris:~# zfs destroy mypool/mydata1 Back to top Exercise Z.5: ZFS Encryption Task: Encrypt sensitive data. Lab: Explore basic ZFS encryption. This lab only covers the basics of ZFS Encryption. In particular it does not cover various aspects of key management. Please see the ZFS Adminastrion Manual and the zfs_encrypt(1M) manual page for more detail on this functionality. Back to top root@solaris:~# zfs create -o encryption=on mypool/data2 Enter passphrase for 'mypool/data2': ******** Enter again: ******** root@solaris:~# Creation of a descendent dataset shows that encryption is inherited from the parent: root@solaris:~# zfs create mypool/data2/data3 root@solaris:~# zfs get -r encryption,keysource,keystatus,checksum mypool/data2 NAME PROPERTY VALUE SOURCE mypool/data2 encryption on local mypool/data2 keysource passphrase,prompt local mypool/data2 keystatus available - mypool/data2 checksum sha256-mac local mypool/data2/data3 encryption on inherited from mypool/data2 mypool/data2/data3 keysource passphrase,prompt inherited from mypool/data2 mypool/data2/data3 keystatus available - mypool/data2/data3 checksum sha256-mac inherited from mypool/data2 You will find the online manual page zfs_encrypt(1M) contains examples. In particular, if time permits during this lab session you may wish to explore the changing of a key using "zfs key -c mypool/data2". Exercise Z.6: Shadow Migration Shadow Migration allows you to migrate data from an old file system to a new file system while simultaneously allowing access and modification to the new file system during the process. You can use Shadow Migration to migrate a local or remote UFS or ZFS file system to a local file system. Task: You wish to migrate data from one file system (UFS, ZFS, VxFS) to ZFS while mainaining access to it. Lab: Create the infrastructure for shadow migration and transfer one file system into another. First create the file system you want to migrate root@solaris:~# zpool create oldstuff c3t4d0 root@solaris:~# zfs create oldstuff/forgotten Then populate it with some files: root@solaris:~# cd /var/adm root@solaris:/var/adm# find . -print | cpio -pdv /oldstuff/forgotten You need the shadow-migration package installed: root@solaris:~# pkg install shadow-migration Packages to install: 1 Create boot environment: No Create backup boot environment: No Services to change: 1 DOWNLOAD PKGS FILES XFER (MB) Completed 1/1 14/14 0.2/0.2 PHASE ACTIONS Install Phase 39/39 PHASE ITEMS Package State Update Phase 1/1 Image State Update Phase 2/2 You then enable the shadowd service: root@solaris:~# svcadm enable shadowd root@solaris:~# svcs shadowd STATE STIME FMRI online 7:16:09 svc:/system/filesystem/shadowd:default Set the filesystem to be migrated to read-only root@solaris:~# zfs set readonly=on oldstuff/forgotten Create a new zfs file system with the shadow property set to the file system to be migrated: root@solaris:~# zfs create -o shadow=file:///oldstuff/forgotten mypool/remembered Use the shadowstat(1M) command to see the progress of the migration: root@solaris:~# shadowstat EST BYTES BYTES ELAPSED DATASET XFRD LEFT ERRORS TIME mypool/remembered 92.5M - - 00:00:59 mypool/remembered 99.1M 302M - 00:01:09 mypool/remembered 109M 260M - 00:01:19 mypool/remembered 133M 304M - 00:01:29 mypool/remembered 149M 339M - 00:01:39 mypool/remembered 156M 86.4M - 00:01:49 mypool/remembered 156M 8E 29 (completed) Note that if you had created /mypool/remembered as encrypted, this would be the preferred method of encrypting existing data. Similarly for compressing or deduplicating existing data. The procedure for migrating a file system over NFS is similar - see the ZFS Administration manual. That concludes this lab session.

  Read the article

• Algorithm for a lucky game [on hold]

  - by Ronnie

  Assume we have the following Keno(lottery type) game: From 80 numbers(from 1 to 80), 20 are being drawn. The players choose 1 or 2 or 3..... or 12 numbers to play(12 categories). If they choose for example 4 then they win if they predict correctly a certain amount of numbers(2,3 or 4) from the 4 they have played and lose if the predict only 1 or 0 numbers. They win X times their money accordingly to some predefined factor depending on how many numbers they predict from each category. The same with the other categories. And e.g 11 out of 11 gives 250000 times your money and 12 out of 12 gives 1000000 your money. So the company would want to avoid winnings so high. Every draw by the company is being made every 5 minutes and in each draw around 120000 (let's say) different predictions(Keno tickets) are being played. Let's assume 12000 are being played in category 10 and 12000 in category 11 and also 12000 in category 12. I'm wondering if there is an algorithm to allow the company that provides the game in the 5 minutes between the drawings, to find a 20 number set, in order to avoid any "12 out of 12" and "11 out of 11" and "11 out of 12" and "10 out of 11" and "10 out of 10" winning ticket. That means is there any algorithm, where in a time of less than 1 minute approximately(in todays hardware), to be able to find a 20 number set so that none of the 12000 12 and 11 and 10 number sets that the players played(in categories 10,11 and 12) contains any winning of "12 out of 12" and "11 out of 11" and "11 out of 12" and "10 out of 11" and "10 out of 10"? Or even better the generalization of the problem: What is the best algorithm(from a perspective of minimal time), to be able to find a Y number set from numbers 1 to Z(e.g Y=20, Z=80) so that none of the X sets of K-numbers that are being played(in category K) contains more than K-m numbers from the Y-set? (Note that for Y=K and m=1 there is a practical algorithm.)

  Read the article

• Filtering GridViewComboBoxColumn in RadGridView for WPF

  The GridViewComboBox column is used to display lookup data in user friendly manner. For our demo we bind RadGridView for WPF to a collection of custom Location objects. As you may notice – each location has a selectable Country field.  Here is the underlying ‘data model’: public class Location {  public int CountryID { get; set; }  public string CityName { get; set; } } public class Country {  public int ID { get; set; }  public string Name { get; set; } }   The location object contains the integer CountryID. Each CountryID corresponds to a certain country and with the help of GridViewComboBoxColumn we see some human readable country names instead of the underlying numeric IDs. Now The Problem: Unfortunately the filter control does not know that our Country IDs are associated with Country objects, so it displays the ...Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

  Read the article

• Lost in Translation

  - by antony.reynolds

  Using the Correct Character Set for the SOA Suite Database A couple of years ago I spent a wonderful week in Tel Aviv helping with the first Oracle BAM implementation in Israel.  Although everyone I interacted spoke better English than I did, the screens and data for the implementation were all in Hebrew, meaning the Hebrew alphabet.  Over the week I learnt to recognize a few Hebrew words, enough to enable me to test what we were doing.  So I knew SOA Suite worked OK with non-English and non-Latin character sets so I was suspicious recently when a customer was having data corruption of non-Latin characters.  On investigation it turned out that the data received correctly in the SOA Suite, but then it was corrupted after being stored in the database. A little investigation revealed that the customer was using the default database character set, which is “WE8ISO8859P1” which, as the name suggests only supports West European 8-bit characters.  What was happening was that when the customer had installed his SOA repository he had ignored the message that his database was not using AL32UTF as the character. After changing the character set on his database he no longer saw the corruption of non-English character data. So the moral of this story is Always install the SOA Repository in to an AL32UTF8 Database This is true for both SOA Suite 10g and 11g.  Ignore it at your peril, because you never know when you will need to support Hebrew, or Japanese or another multi-byte character set.

  Read the article

• Gesture Detector not firing

  - by Tyler

  So I'm trying to create a input class that implements a InputHandler & GestureListener in order to support both Android & Desktop. The problem is that not all the methods are being called properly. Here is the input class definition & a couple of the methods: public class InputHandler implements GestureListener, InputProcessor{ ... public InputHandler(OrthographicCamera camera, Map m, Player play, Vector2 maxPos) { ... @Override public boolean zoom(float originalDistance, float currentDistance) { //this.zoom = true; this.zoomRatio = originalDistance / currentDistance; cam.zoom = cam.zoom * zoomRatio; Gdx.app.log("GestureDetector", "Zoom - ratio: " + zoomRatio); return true; } @Override public boolean touchDown(int x, int y, int pointerNum, int button) { booleanConditions[TOUCH_EVENT] = true; this.inputButton = button; this.inputFingerNum = pointerNum; this.lastTouchEventLoc.set(x,y); this.currentCursorPos.set(x,y); if(pointerNum == 1) { //this.fingerOne = true; this.fOnePosition.set(x, y); } else if(pointerNum == 2) { //this.fingerTwo = true; this.fTwoPosition.set(x,y); } Gdx.app.log("GestureDetector", "touch down at " + x + ", " + y + ", pointer: " + pointerNum); return true; } The touchDown event always occurs but I can never trigger Zoom (or pan among others...). The following is where I register and create the input handler in the "Game Screen". public class GameScreen implements Screen { ... this.inputHandler = new InputHandler(this.cam, this.map, this.player, this.map.maxCamPos); Gdx.input.setInputProcessor(this.inputHandler); Anyone have any ideas why zoom, pan, etc... are not triggering? Thanks!

  Read the article

• SharpDx: using maximized RenderForm

  - by ceiling cat

  I'm trying to learn DirectX via SharpDX, very new to this. What I want to do is be able to draw 2D shapes for a game I'm trying to make. So I started with the demo "MiniRect" that came with SharpDX. Since I want my game to be full-screen, I changed the RenderForm to be maximized (using WindowState) and set the FromBorderStyle to None. I noticed that even if the form is set to maximized, it's size is always 800 by 600. In my renderloop, if I specify the location for the rectangle has 400 by 300, it is drawn in the middle of the screen. If I try to set the location via mouse-click (using the RenderForm's MouseClick event, there is always an offset present between where the mouse was clicked and where the drawing shows up. My system DPI is set to the standard (96) so there shouldn't be any scaling. But it looks like there is a scaling factor of about 2.4 If it's not the DPI settings, does anyone have any idea what this be related to? The problem doesnt happen if the RenderForm is not maximized. Is there another way to be drawing full-screen using SharpDX? Thanks

  Read the article

• Collision detection on a 2D hexagonal grid

  - by SundayMonday

  I'm making a casual grid-based 2D iPhone game using Cocos2D. The grid is a "staggered" hex-like grid consisting of uniformly sized and spaced discs. It looks something like this. I've stored the grid in a 2D array. Also I have a concept of "surrounding" grid cells. Namely the six grid cells surrounding a particular cell (except those on the boundries which can have less than six). Anyways I'm testing some collision detection and it's not working out as well as I had planned. Here's how I currently do collision detection for a moving disc that's approaching the stationary group of discs: Calculate ij-coordinates of grid cell closest to moving cell using moving cell's xy-position Get list of surrounding grid cells using ij-coordinates Examine the surrounding cells. If they're all empty then no collision If we have some non-empty surrounding cells then compare the distance between the disc centers to some minimum distance required for a collision If there's a collision then place the moving disc in grid cell ij So this works but not too well. I've considered a potentially simpler brute force approach where I just compare the moving disc to all stationary discs at each step of the game loop. This is probably feasible in terms of performance since the stationary disc count is 300 max. If not then some space-partitioning data structure could be used however that feels too complex. What are some common approaches and best practices to collision detection in a game like this?

  Read the article

• Is it a "pattern smell" to put getters like "FullName" or "FormattedPhoneNumber" in your model?

  - by DanM

  I'm working on an ASP.NET MVC app, and I've been getting into the habit of putting what seem like helpful and convenient getters into my model/entity classes. For example: public class Member { public int Id { get; set; } public string FirstName { get; set; } public string LastName { get; set; } public string PhoneNumber { get; set; } public string FullName { get { return FirstName + " " + LastName; } } public string FormattedPhoneNumber { get { return "(" + PhoneNumber.Substring(0, 3) + ") " + PhoneNumber.Substring(3, 3) + "-" + PhoneNumber.Substring(6); } } } I'm wondering people think about the FullName and FormattedPhoneNumber getters. They make it very easy to create standardized data formats throughout the app, and they seem to save a lot of repeated code, but it could definitely be argued that data format is something that should be handled in mapping from model to view-model. In fact, I was originally applying these data formats in my service layer where I do my mapping, but it was becoming a burden to constantly have to write formatters then apply them in many different places. E.g., I use "Full Name" in most views, and having to type something like model.FullName = MappingUtilities.GetFullName(entity.FirstName, entity.LastName); all over the place seemed a lot less elegant than just typing model.FullName = entity.FullName (or, if you use something like AutoMapper, potentially not typing anything at all). So, where do you draw the line when it comes to data formatting. Is it "okay" to do data formatting in your model or is that a "pattern smell"? Note: I definitely do not have any html in my model. I use html helpers for that. I'm strictly talking about formatting or combining data (and especially data that is frequently used).

  Read the article

• null pointers vs. Null Object Pattern

  - by GlenH7

  Attribution: This grew out of a related P.SE question My background is in C / C++, but I have worked a fair amount in Java and am currently coding C#. Because of my C background, checking passed and returned pointers is second-hand, but I acknowledge it biases my point of view. I recently saw mention of the Null Object Pattern where the idea is than an object is always returned. Normal case returns the expected, populated object and the error case returns empty object instead of a null pointer. The premise being that the calling function will always have some sort of object to access and therefore avoid null access memory violations. So what are the pros / cons of a null check versus using the Null Object Pattern? I can see cleaner calling code with the NOP, but I can also see where it would create hidden failures that don't otherwise get raised. I would rather have my application fail hard (aka an exception) while I'm developing it than have a silent mistake escape into the wild. Can't the Null Object Pattern have similar problems as not performing a null check? Many of the objects I have worked with hold objects or containers of their own. It seems like I would have to have a special case to guarantee all of the main object's containers had empty objects of their own. Seems like this could get ugly with multiple layers of nesting.

  Read the article

• WPF Applications &ndash; Handling the Unhandled

  - by David Totzke

  Instead of just letting your application crash, you can attach a method to the DispatcherUnhandledExceptionEventHandler and one to the AppDomain.Current.UnhandledException.  You wire these up in the code behind of your application which by default is App.xaml.cs.  You can log these errors or throw up a message Don Box and tell the user what happened.  Then you shut down the app gracefully.  You shut it down because something bad happened that you weren’t expecting and at this point there is no guarantee as to the state of the stack or memory or anything really.  All bets are off. If, on the other hand, the method for the UnhandledException is empty and the method for the DispatcherUnhandledEventHandler ends up in a call to a method called LogError() and the LogError() method is FUCKING EMPTY, and you just swallow the exceptions and keep on running, then, not so much.  I spent nearly a day trying to track down a bug that would have been obvious had something been logged or if it just crashed.  It’s my own fault I suppose.  I knew these were hooked up.  I just never suspected that there wouldn’t be any implementation at all.  Live and learn. Customs Man at Heathrow: Anything to declare, Sir? Jekyll and Hyde: Man has not evolved an inch from the slime that spawned him. Customs Man at Heathrow: Very Good, Sir. I tend to agree. Dave Just because I can…

  Read the article

• Should one always know what an API is doing just by looking at the code?

  - by markmnl

  Recently I have been developing my own API and with that invested interest in API design I have been keenly interested how I can improve my API design. One aspect that has come up a couple times is (not by users of my API but in my observing discussion about the topic): one should know just by looking at the code calling the API what it is doing. For example see this discussion on GitHub for the discourse repo, it goes something like: foo.update_pinned(true, true); Just by looking at the code (without knowing the parameter names, documentation etc.) one cannot guess what it is going to do - what does the 2nd argument mean? The suggested improvement is to have something like: foo.pin() foo.unpin() foo.pin_globally() And that clears things up (the 2nd arg was whether to pin foo globally, I am guessing), and I agree in this case the later would certainly be an improvement. However I believe there can be instances where methods to set different but logically related state would be better exposed as one method call rather than separate ones, even though you would not know what it is doing just by looking at the code. (So you would have to resort to looking at the parameter names and documentation to find out - which personally I would always do no matter what if I am unfamiliar with an API). For example I expose one method SetVisibility(bool, string, bool) on a FalconPeer and I acknowledge just looking at the line: falconPeer.SetVisibility(true, "aerw3", true); You would have no idea what it is doing. It is setting 3 different values that control the "visibility" of the falconPeer in the logical sense: accept join requests, only with password and reply to discovery requests. Splitting this out into 3 method calls could lead to a user of the API to set one aspect of "visibility" forgetting to set others that I force them to think about by only exposing the one method to set all aspects of "visibility". Furthermore when the user wants to change one aspect they almost always will want to change another aspect and can now do so in one call.

  Read the article

• java UnitilsException: Executed scripts table "PUBLIC"."DBMAINTAIN_SCRIPTS" doesn't exist yet or is invalid [closed]

  - by Philippe

  I want use Unitils for testing my JAVA program, i have following error message "UnitilsException: Executed scripts table "PUBLIC"."DBMAINTAIN_SCRIPTS" doesn't exist yet or is invalid" My table is into an DDL file, and table is not created Could you says me if dataSetStructureGenerator.xsd.dirName=src/test/resources/dataset-schema properties is still active in unitils 3.3 ? My EMPLOYEE table is not created and DBMAINTAIN_SCRIPTS not created too Where is my mistake ? My DDL file SET REFERENTIAL_INTEGRITY FALSE; SET DATABASE COLLATION "French"; SET SCHEMA PUBLIC; CREATE TABLE DBMAINTAIN_SCRIPTS (FILE_NAME VARCHAR2(150), FILE_LAST_MODIFIED_AT INTEGER, CHECKSUM VARCHAR2(50), EXECUTED_AT VARCHAR2(20), SUCCEEDED INTEGER); CREATE TABLE EMPLOYEES(ID IDENTITY NOT NULL,NAME VARCHAR(20),TITLE VARCHAR(20),SALARY DOUBLE,NI INTEGER NOT NULL) My unitils properties file # comments documenting these unitils configuration properties removed for # brevity. look for commenting in unitils-default.properties in the root of the # unitils jar if needed. unitils.modules=database,dbunit,easymock,inject unitils.module.hibernate.enabled=false unitils.module.spring.enabled=false # these placeholders are set in avaje.properties #gere la configuration DBUNIT database.driverClassName=org.hsqldb.jdbcDriver database.url=jdbc:hsqldb:mem:unitils-example database.schemaNames=PUBLIC database.userName=SA database.password= database.dialect=hsqldb # unitils will construct the test database using the ddl file found in this # directory dbMaintainer.fileScriptSource.scripts.location=src/main/resources updateDataBaseSchema.enabled=true sequenceUpdater.sequencevalue.lowestacceptable=100 dataSetStructureGenerator.xsd.dirName=src/test/resources/dataset-schema #dbMaintainer.autoCreateExecutedScriptsTable property to true

  Read the article

• Gnome trash on cifs mount random behaviour

  - by BobPenguin

  Hello everyone, I'm seeing some weird behaviour in Ubuntu 10.04. I have a cifs mount that's mounted by fstab as follows: //192.168.1.1/share /media/storage cifs_netdev,username=guest,password="",uid=1000,guid=100,file_mode=0777,dir_mode=0777 0 0 I can mount the share using: sudo mount -a my user can then access it, create and delete files. The deleted files appear in the gnome trash applet. A folder /media/storage/.Trash-1000 is created automatically. When I log out, restart the machine and log in, the cifs share is mounted but the trash applet is empty. If I unmount the share with sudo umount /media/share then remount with sudo mount -a the trash applet displays the contents of the .trash-1000 folder! It gets stranger...sometimes after umount then mount -a the trash is STILL empty, but another round of umount then mount -a fixes it. It seems like the trash applet is "forgetting" to scan the /media/storage mount point and is not always finding the .trash-1000 folder at that mount point. Even when the trash applet is not displaying any trash from /media/storage/.trash-1000 I can still delete things from the /media/storage and they're moved to the .trash-1000 folder. So I conclude there's a bug in the trash applet...anyone know how to fix it?

  Read the article

• Retrieve the full ASP.NET Form Buffer as a String

  - by Rick Strahl

  Did it again today: For logging purposes I needed to capture the full Request.Form data as a string and while it’s pretty easy to retrieve the buffer it always takes me a few minutes to remember how to do it. So I finally wrote a small helper function to accomplish this since this comes up rather frequently especially in debugging scenarios or in the immediate window. Here’s the quick function to get the form buffer as string: /// <summary> /// Returns the content of the POST buffer as string /// </summary> /// <returns></returns> public static string FormBufferToString() { HttpRequest Request = HttpContext.Current.Request; if (Request.TotalBytes > 0) return Encoding.Default.GetString(Request.BinaryRead(Request.TotalBytes)); return string.Empty; } Clearly a simple task, but handy to have in your library for reuse. You probably don’t want to call this if you have a massive inbound form buffer, or if the data you’re retrieving is binary. It’s probably a good idea to check the inbound content type before calling this function with something like this: var formBuffer = string.Empty; if (Request.ContentType.StartsWith("text/") || Request.ContentType == "application/x-www-form-urlencoded") ) { formBuffer = FormBufferToString(); } to ensure you’re working only on content types you can actually view as text. Now if I can only remember the name of this function in my library – it’s part of the static WebUtils class in the West Wind Web Toolkit if you want to check out a number of other useful Web helper functions.© Rick Strahl, West Wind Technologies, 2005-2011Posted in ASP.NET  

  Read the article

• Make a controller a superclass in MVC design pattern

  - by Nikola

  I am really confused how to handle this. I have: model.Outsider model.SubContractor (which extends Outsider) Basically, Outsider would mean Supplier, but SubContractor is not a Supplier itself so I had to divide it somehow. I used to have model.Outsider (super class of the two bellow) model.Supplier model.SubContractor But Supplier didn't have any unique fields so I have removed it (Was this correct?) So, continuing, I have db layer which has: db.DBOutsider db.DBSubContractor (which again extends the top one) And I have no place to put my Supplier methods. I can do that in DBOutsider, but then DBSubContractor (which extends DBOutsider) would get unnecessary methods. Do I create a DBSupplier even though there is no such class in the model layer? Then again, going to controller layer. It is the same situation as db layer. I have OutsiderController and SubContractorController (which extends the first one) (is this correct in first place? to have an extended controller?). But I have no place to put the methods which are concerned with Supplier and if I put them in the OutsiderController the SubContractorController would recieve unneccessary methods. At the moment I am going for the extra DBSupplier and SupplierController classes, but I have no idea if this is the correct way. Basically what perplexes me is the "empty" Supplier. Since it is supposed to be an Outsider but has no extra methods or fields, should there be an empty class?

  Read the article

• need explanation on amortization in algorithm

  - by Pradeep

  I am a learning algorithm analysis and came across a analysis tool for understanding the running time of an algorithm with widely varying performance which is called as amortization. The autor quotes " An array with upper bound of n elements, with a fixed bound N, on it size. Operation clear takes O(n) time, since we should dereference all the elements in the array in order to really empty it. " The above statement is clear and valid. Now consider the next content: "Now consider a series of n operations on an initially empty array. if we take the worst case viewpoint, the running time is O(n^2), since the worst case of a sigle clear operation in the series is O(n) and there may be as many as O(n) clear operations in the series." From the above statement how is the time complexity O(n^2)? I did not understand the logic behind it. if 'n' operations are performed how is it O(n ^2)? Please explain what the autor is trying to convey..

  Read the article

• Web Sites All Start When Debugging a Web Site - Visual Studio 2010

  - by Daniel Lackey

  I wanted to blog about this because it was an annoyance to me and I couldn't figure out why for quite some time. Have you ever tried debugging one web application in your solution but when you do, all other web sites in your solution build and then start up their respective Visual Studio Development Server? It's not a major problem, but it adds time to waiting for what you are actually trying to debug to start up. After digging through Visual Studio 2010 settings, I finally found the option to turn it off. It is called Always Start When Debugging and is located in the Properties pane for the web project (click on the project .proj file in Visual Studio IDE). This is set to True by default each time you create a new Web Application project. Setting this to false will solve your problems. You will need to set this to false for all web applications in your solution as shown below: In addition, you can set properties on which port the development server uses each time it debugs. This is helpful if you want the port to stay the same for testing purposes. In contrast, you can set it to use a dynamic port each time so if you have a co-worker that is debugging it on a different session on the same server, you won't run into any problems with using the same port. The machine won't allow you to debug two sessions on the same port. Pretty basic stuff but it seemed like a really quirky setting to me.

  Read the article

• Debugging the NetBeans Platform

  - by Geertjan

  Once you've set up the NetBeans Platform sources as your NetBeans Platform, you're able to debug the NetBeans Platform itself. That's an occasional question (certainly not a frequent question) on the mailing list and in NetBeans Platform courses: "Is it possible to debug the NetBeans Platform?" Well, here's how: Firstly, set up the NetBeans Platform sources as your NetBeans Platform. Now, open into NetBeans IDE the NetBeans module where you'd like to place a breakpoint. That in itself is the hardest part of this task. I.e., you know you want to debug the NetBeans Platform, but have no idea where to place your breakpoint. One way to figure that out, from 7.1 onwards, is to take a visual snapshot of the NetBeans Platform and then analyze that snapshot in NetBeans IDE. To do this, right-click a module that you've set as using the NetBeans Platform sources as your NetBeans Platform and then choose Debug. The application, i.e., the NetBeans Platform, including your custom module, starts up and you'll see this, i.e., NetBeans IDE in debug mode together with your NetBeans Platform application:Notice there's a new toolbar button (new in NetBeans IDE 7.1) that resembles an orange camera. Click that button and the IDE creates a visual snapshot of the running application, which in this case is the NetBeans Platform. When you click components in the visual snapshot, the Navigator and Properties window display information about the related GUI component: By clicking the above components, you can end up identifying the component you'd like to debug and even the module where it is found. Open that module. Set a breakpoint on the line of interest. Right-click the module again and choose Debug. A debug session starts and when the breakpoint is hit, the Debugger in the IDE will open and there you can step through the NetBeans Platform sources.

  Read the article

• Preview Chitika Premium Ads On Your Website Quickly

  - by Gopinath

  Google AdSense is an excellent option for publishers like us to monetize traffic. As Google AdSense allow only 3 ad units per page, we have good amount of space left empty on the blog. Why not we use this empty space to earn some revenue(make sure that you are not annoying your visitors with too many ads)? On Tech Dreams today we started experimenting with Chitika Premium Ads to displays advertisements for visitors landing on us through search engines. Chitika Premium Ads are displayed only to US visitors who finds our pages through search engines. Visitors from outside USA does not see these ads anywhere on our site. We being in India, how to preview the Chitika ads on our site? To preview Chitika ads add #chitikatest at the end of the url. For example to preview the ads on Tech Dreams I use the url http://techdreams.org/#chitikatest The above url displays default list of ads Chitika displays. But if you want to see preview of ads for a specific keyword you can append it at the end of the url. Here is another example http://www.techdreams.org/#chitikatest=ipad   Do You Know What The Word “Chitika” Means? What does Chitika mean? When Chitika co-founders, Venkat Kolluri and Alden DoRosario left Lycos in 2003 to start their own company, they sought a name that would suggest the speed with which its customers would be able to put up ads on their Web sites. Chitika, which means “snap of the fingers” in Telugu (a South Indian language), captured this sentiment and Chitika Inc. was born (via) This article titled,Preview Chitika Premium Ads On Your Website Quickly, was originally published at Tech Dreams. Grab our rss feed or fan us on Facebook to get updates from us.

  Read the article

• Kubuntu 11.04 bad experience, Gimp crashes and other bugs

  - by giowck

  I installed Kubuntu 11.04 64bit today. First let me expose some issues, this is not a rant, just some observations on Kubuntu 11.04 :) Flash doesn't work. The package "flashplugin-installer" was installed by rekonq. But still no flash. Additional Drivers (jockey-kde) doesn't show up automatically after first login. I tried to delete a large file (19,2 GB), an error appeared: "Please empty the trash first, no more space available" or something like that, but you know what? My trash was empty! (Then I found in Dolphin the settings to increment the max size of the trash). Amarok has no play/pause/forward/back buttons, only after changing settings to show those buttons on the top bar. GTK applications like ubuntu software center, inkscape... are in english, but my default language is "german". Only gimp allows to install the "de" language pack. The numblock turns off after each restart. In the KDE Control Center, the "remember last state" of numblock is set. But this is not working. I had some crashes: Nepomuk, Policy-kit, plasma-workspace and gimp. But now to the important stuff. I really need Gimp to work. After starting it, I get a crash: giowck@giowck-desktop:~$ gimp (gimp:1899): GLib-WARNING **: /build/buildd/glib2.0-2.28.6/./glib/goption.c:2132: ignoring no-arg, optional-arg or filename flags (8) on option of type 0 Speicherzugriffsfehler (in English: "Memory error") What can I do to run Gimp? Thanks

  Read the article

• Webmaster Tools, www and no-www, duplicate content and subdomains

  - by Jay

  I have not come to any conclusive answers on the following after many hours of research on many websites to the specific issue that I am trying to figure out. My company has two websites a main one at www.example.com and one at subdomain.example.com which is a subdomain of the first and is our self hosted blog. The way Google sees these with the www or no-www (called naked for now on) is that each of these actually are different when the www or naked version is used/not used in the front of the domain. I completely understand this. It is also advised that both should be set up in the Google Webmaster Tools, which I have done. Correct me if I am wrong on that in regard to having both set up. Now the way it appears is that we can set a preferred domain up in Webmaster Tools only at the root domain level. The subdomain can not have this and actually says the following "Restricted to root level domains only". So it appears that the domain should follow what the root domain says which on our preferred one says to display the www.example.com. and not the naked version. That is one issue I have in that one displays one way and the other displays another. Is it that we have the wrong redirects in place for the subdomain? Another question is does this have any affect on SEO in regards to duplicate content on the web in how we have set this up?

  Read the article

< Previous Page | 318 319 320 321 322 323 324 325 326 327 328 329  | Next Page >