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• Numpy: Sorting a multidimensional array by a multidimensional array

  - by JD Long

  Forgive me if this is redundant or super basic. I'm coming to Python/Numpy from R and having a hard time flipping things around in my head. I have a n dimensional array which I want to sort using another n dimensional array of index values. I know I could wrap this in a loop but it seems like there should be a really concise Numpyonic way of beating this into submission. Here's my example code to set up the problem where n=2: a1 = random.standard_normal(size=[2,5]) index = array([[0,1,2,4,3] , [0,1,2,3,4] ]) so now I have a 2 x 5 array of random numbers and a 2 x 5 index. I've read the help for take() about 10 times now but my brain is not groking it, obviously. I thought this might get me there: take(a1, index) array([[ 0.29589188, -0.71279375, -0.18154864, -1.12184984, 0.25698875], [ 0.29589188, -0.71279375, -0.18154864, 0.25698875, -1.12184984]]) but that's clearly reordering only the first element (I presume because of flattening). Any tips on how I get from where I am to a solution that sorts element 0 of a1 by element 0 of the index ... element n?

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• Fetch request error: no entity? Probably easy, but help!

  - by cksubs

  Hi, I'm going through the Stanford iPhone course. I'm on the second Paparazzi assignment. I'm getting this error: * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'executeFetchRequest:error: A fetch request must have an entity.' I've copied a lot of the code from this walkthrough site. Running his source code works perfectly, and at this point my code is pretty much exactly the same as his. But it throws that error. See below for the relavent bits: // Create FetchRequest NSFetchRequest *request = [[NSFetchRequest alloc] init]; NSEntityDescription *entity = [NSEntityDescription entityForName:@"Person" inManagedObjectContext:context]; [request setEntity:entity]; // Set the sort descriptor NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"personName" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [request setSortDescriptors:sortDescriptors]; [sortDescriptors release]; [sortDescriptor release]; // set up NSFetchedResultsController to hold the fetch NSFetchedResultsController *frc = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:context sectionNameKeyPath:nil cacheName:@"personCache"]; // execute the fetch NSError *error; NSLog(@"Prints Here"); [frc performFetch:&error]; NSLog(@"Doesn't Print Here"); I'm clearly setting the entity with [request setEntity:entity]. So the error has me stumped. Is there something I'm missing? Maybe in another file? I don't know. I'm still so confused with Objective-C.... Thanks.

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• Generating all unique combinations for "drive ya nuts" puzzle

  - by Yuval A

  A while back I wrote a simple python program to brute-force the single solution for the drive ya nuts puzzle. The puzzle consists of 7 hexagons with the numbers 1-6 on them, and all pieces must be aligned so that each number is adjacent to the same number on the next piece. The puzzle has ~1.4G non-unique possibilities: you have 7! options to sort the pieces by order (for example, center=0, top=1, continuing in clockwise order...). After you sorted the pieces, you can rotate each piece in 6 ways (each piece is a hexagon), so you get 6**7 possible rotations for a given permutation of the 7 pieces. Totalling: 7!*(6**7)=~1.4G possibilities. The following python code generates these possible solutions: def rotations(p): for i in range(len(p)): yield p[i:] + p[:i] def permutations(l): if len(l)<=1: yield l else: for perm in permutations(l[1:]): for i in range(len(perm)+1): yield perm[:i] + l[0:1] + perm[i:] def constructs(l): for p in permutations(l): for c in product(*(rotations(x) for x in p)): yield c However, note that the puzzle has only ~0.2G unique possible solutions, as you must divide the total number of possibilities by 6 since each possible solution is equivalent to 5 other solutions (simply rotate the entire puzzle by 1/6 a turn). Is there a better way to generate only the unique possibilities for this puzzle?

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• Is this a good approach to address double-base64-encoding?

  - by Freiheit

  My software understands attachments, like PNGs attached to user records. These attachments are usually sent in from outside sources as a Base64 encoded string. The database stores whatever data it is given, Base64 encoded or not. When I serve up the attachment for download I do this: if (Base64.isBase64(data)) { data = Base64.decodeBase64(data); } There is a potential for data that is double encoded. For instance the sender of a message had base64 encoded data, then encoded it again when building the message to send to me. I think the following code would address that circumstance: while (Base64.isBase64(data)) { data = Base64.decodeBase64(data); } So if data is encoded multiple times, it would be decoded until its in its 'raw' state and then served up for download. Is this approach an acceptable way to address that problem? Ideally some sort of checking could happen at the edge when I receive attachment data, but that will take more time. This looping seems to be a faster way to do it. The 'Base64' library is Apache Commons: http://commons.apache.org/codec/apidocs/org/apache/commons/codec/binary/Base64.html I trust it to properly identify Base64 encoded data.

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• Sorted exsl:node-set. Return node by it position.

  - by kalininew

  Good afternoon, gentlemen. Help me solve a very simple task. I have a set of nodes <menuList> <mode name="aasdf"/> <mode name="vfssdd"/> <mode name="aswer"/> <mode name="ddffe"/> <mode name="ffrthjhj"/> <mode name="dfdf"/> <mode name="vbdg"/> <mode name="wewer"/> <mode name="mkiiu"/> <mode name="yhtyh"/> and so on... </menuList> I have it sorted now this way <xsl:variable name="rtf"> <xsl:for-each select="//menuList/mode"> <xsl:sort data-type="text" order="ascending" select="@name"/> <xsl:value-of select="@name"/> </xsl:for-each> </xsl:variable> Now I need to get an arbitrary element in the sorted array to the number of its position. I write code <xsl:value-of select="exsl:node-set($rtf)[position() = 3]"/> and get a response error. How to do it right?

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• Any way to identify a redirect when using jQuery's $.ajax() or $.getScript() methods?

  - by Bungle

  Within my company's online application, we've set up a JSONP-based API that returns some data that is used by a bookmarklet I'm developing. Here is a quick test page I set up that hits the API URL using jQuery's $.ajax() method: http://troy.onespot.com/static/3915/index.html If you look at the requests using Firebug's "Net" tab (or the like), you'll see that what's happening is that the URL is requested successfully, but since our app redirects any unauthorized users to a login page, the login page is also requested by the browser and seemingly interpreted as JavaScript. This inevitably causes an exception since the login page is HTML, not JavaScript. Basically, I'm looking for any sort of hook to determine when the request results in a redirect - some way to determine if the URL resolved to a JSONP response (which will execute a method I've predefined in the bookmarklet script) or if it resulted in a redirect. I tried wrapping the $.ajax() method in a try {} catch(e) {} block, but that doesn't trap the exception, I'm assuming because the requests were successful, just not the parsing of the login page as JavaScript. Is there anywhere I could use a try {} catch(e) {} block, or any property of $.ajax() that might allow me to hone in on the exception or otherwise determine that I've been redirected? I actually doubt this is possible, since $.getScript() (or the equivalent setup of $.ajax()) just loads a script dynamically, and can't inspect the response headers since it's cross-domain and not truly AJAX: http://api.jquery.com/jQuery.getScript/ My alternative would be to just fire off the $.ajax() for a period of time until I either get the JSONP callback or don't, and in the latter case, assume the user is not logged in and prompt them to do so. I don't like that method, though, since it would result in a lot of unnecessary requests to the app server, and would also pile up the JavaScript exceptions in the meantime. Thanks for any suggestions!

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• Serial Communication between Java RXTX and Arduino

  - by SharpBarb

  I'm trying to communicate between my PC (Windows 7 using Netbeans and RXTX) with an Arduino Pro, using the serial port. The Arduino is actually connected to the PC using an FTDI cable. The code is based on the Java SimpleRead.Java found here. Currently the Arduino simply prints out a string when it starts up. My Java program should print the number of bytes that have been read and then print out the contents. The Java program works, sort of... If the string is long (10 bytes or so) the output will get broken up. So if on the Arduino I print Serial.println("123456789123456789"); //20 bytes including '\r' and '\n' The output of my Java program may look something like: Number of Bytes: 15 1234567891234 Number of Bytes: 5 56789 or Number of Bytes: 12 1234567891 Number of Bytes: 8 23456789 I'm thinking it's a timing problem, because when I manually go through the code using the debugger, the result string is always what it should be: one 20 byte string. I've been messing with various things but I haven't been able to fix the problem. Here is the part of the code that is giving me problems: static int baudrate = 9600, dataBits = SerialPort.DATABITS_8, stopBits = SerialPort.STOPBITS_1, parity = SerialPort.PARITY_NONE; byte[] readBuffer = new byte[128]; ... ... public void serialEvent(SerialPortEvent event) { if (event.getEventType() == SerialPortEvent.DATA_AVAILABLE) { try { if (input.available() > 0) { //Read the InputStream and return the number of bytes read numBytes = input.read(readBuffer); String result = new String(readBuffer,0,numBytes); System.out.println("Number of Bytes: " + numBytes); System.out.println(result); } } catch (IOException e) { System.out.println("Data Available Exception"); } }

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• Distance between Long Lat coord using SQLITE

  - by munchine

  I've got an sqlite db with long and lat of shops and I want to find out the closest 5 shops. So the following code works fine. if(sqlite3_prepare_v2(db, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK) { while (sqlite3_step(compiledStatement) == SQLITE_ROW) { NSString *branchStr = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 0)]; NSNumber *fLat = [NSNumber numberWithFloat:(float)sqlite3_column_double(compiledStatement, 1)]; NSNumber *fLong = [NSNumber numberWithFloat:(float)sqlite3_column_double(compiledStatement, 2)]; NSLog(@"Address %@, Lat = %@, Long = %@", branchStr, fLat, fLong); CLLocation *location1 = [[CLLocation alloc] initWithLatitude:currentLocation.coordinate.latitude longitude:currentLocation.coordinate.longitude]; CLLocation *location2 = [[CLLocation alloc] initWithLatitude:[fLat floatValue] longitude:[fLong floatValue]]; NSLog(@"Distance i meters: %f", [location1 getDistanceFrom:location2]); [location1 release]; [location2 release]; } } I know the distance from where I am to each shop. My question is. Is it better to put the distance back into the sqlite row, I have the row when I step thru the database. How do I do that? Do I use the UPDATE statement? Does someone have a piece of code to help me. I can read the sqlite into an array and then sort the array. Do you recommend this over the above approach? Is this more efficient? Finally, if someone has a better way to get the closest 5 shops, love to hear it.

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• Can anyone tell me about a jQuery modal dialog box library that doesn't suck

  - by Ritesh M Nayak

  jQuery based modal dialog boxes are great as long as you do as much as the example tells you to. I need a jQuery based modal dialog box library that has to have the following characteristics: It should be fast, something like the add and link dialog on StackOverflow. Most libraries take an eternity to load the dialog with its fancy effects and stuff. I want to call it using a script. Show a hidden div or a span element inline. MOst of the libraries talk filling an anchor with rel, class and href=#hiddenDiv sort of things. I need to be able to what I want without adding unnecessary attributes to my anchor. Something like this function showDialog(values) { processToChangeDom(values); changeDivTobeDisplayed(); modalDialog.show(); } It should reflect changes I make to the DOM in the hidden Div. I used facebox and found out that it makes a copy of the hidden div and changes to the DOM doesn't reflect on the modal window. I need to be able call the close modal div using javascript and also attach beforeOpen and afterClose handlers to the action. Does anyone have any suggestions? I have already tried facebox, simplemodal and a whole range of libraries, most of them don't support one or the other of these functions I described above.

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• What Algorithm will Find New Longtail Keywords for *keyword* in PPC

  - by Becci

  I am looking for the algorithm (or combo) that would allow someone to find new longtail PPC search phrases based on say one corekeyword. Eg #1 word word corekeyword eg #2 word corekeyword word Google search tool allows a limited number vertically - mostly of eg#1 (https://adwords.google.com.au/select/KeywordToolExternal) I also know of other PPC apps that allow more volume than google adwords keyword tool, But I want to find other combos that mention the corekeyword & then naturally sort for the highest volume searched. Working example of exact match: corekeyword: copywriter (40,500 searches a month) google will serve up: become a copywriter (480 searches globally/month in english) But if I specifically look up: How to become a copywriter (720 searches a month) This exact longtail keyword phrase has 300 more searches than the 3 word version spat out by google. I want the algorithm to find any other highly search exact longtials like: how to become a copywriter Simply because it was save significant $ finding other longtail keywords after your campaign has been running an made google lots of money. I don't want a concantenation algorithm (I already have one of those), because hypothetically, I don't know what keywords will be that I want to find. Any gurus out there? Becci

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• Pseudo random numbers in php

  - by pg

  I have a function that outputs items in a different order depending on a random number. for example 1/2 of the time Popeye's and its will be #1 on the list and Taco Bell and its logo will be #2 and half the time the it will be the other way around. The problem is that when a user reloads or comes back to the page, the order is re-randomized. $Range here is the number of items in the db, so it's using a random number between 1 and the $range. $random = mt_rand(1,$range); for ($i = 0 ; $i < count($variants); $i++) { $random -= $variants[$i]['weight']; if ($random <= 0) { $chosenoffers[$tag] = $variants[$i]; break; } } I went to the beginning of the session and set this: if (!isset($_SESSION['rannum'])){ $_SESSION['rannum']=rand(1,100); } With the idea that I could replace the mt_rand in the function with some sort of pseudo random generator that used the same 1-100 random number as a seed throughout the session. That way i won't have to rewrite all the code that was already written. Am I barking up the wrong tree or is this a good idea?

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• SimpleDOM sortedXPath date sorting works on localhost but not on remote server.

  - by Imminent

  Here's what i'm trying to do: 1) Take a basic XML page (data.xml) 2) Load it with simpleDOM 3) Use simpleDOM sortedXPath to sort all XML items by their pubDate 4) Display sorted output Here is the code I currently have. My code below outputs exactly what I need when run it on my localhost (XAMPP w/PHP 5.3) but on my remote server (which has at least PHP 5.0+) all is lost and a completely blank page is output. It will output the $xml array with print_r though. Here is my code: <?php include('SimpleDOM.php'); $xml = simpledom_load_file('data.xml'); $dateformat = "D j M, g:ia"; /* print_r($xml); <-array will output on remote server if put here, but alas nothing else beyond this point */ /*Output First 5 items sorted by pubDate*/ foreach($xml->channel->sortedXPath('item','pubDate', SORT_DESC) as $i => $item){ if ($i > 4){ break; } print "<p>This Weeks Deal:<strong> ".$item->title."</strong></p>"; print $item->description; print "<p>Date Posted:<strong> ".date($dateformat, strtotime($item->pubDate))."</strong></p>"; } ?> Like I said, this code seems to work great on my localhost... but not being able to run it on my remote server is making me crazy. Any ideas ?? Any help will be far beyond appreciated.

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• Learning about the low level

  - by Anoners

  I'm interested in learning more about the PC from a lower (machine) level. I graduated from a school which taught us concepts using the Java language which abstracted out that level almost completely. As a result I only learned a bit from the one required assembly language course. In order to cram in ASM and quite a few details about architecture, it was hard to get a very deep picture of what is going on there. At work I focus on unix socket programming in C, so i'm much closer to the hardware now, but I feel I should learn a bit more about what streams really are, how memory management and paging works, what goes on when you call "paint()" on a graphics buffer, etc. I missed out on a lot of this and i'm looking for a good resource to get me started. I've heard a lot about the "Pink Book" by Peter Norton (Programmer's Guide to the IBM PC, Programmer's Guide to inside the PC, etc). It seems like this is on the right track, however the original is quite out dated and the newer ones have had conflicting reviews, with many people saying to stay away from it. I'm not sure what the SO crowd thinks about this book or if they have some suggestions for similar books, online resources, etc that may be good primers for this sort of thing. Any suggestions would be appreciated.

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• Hibernate: order multiple one-to-many relations

  - by Markos Fragkakis

  I have a search screen, using JSF, JBoss Seam and Hibernate underneath. There are columns for A, B and C, where the relations are as follows: A (1< -- ) B (1< -- ) C A has a List< B and B has a List< C (both relations are one-to-many). The UI table supports ordering by any column (ASC or DESC), so I want the results of the query to be ordered. This is the reason I used Lists in the model. However, I got an exception that Hibernate cannot eagerly fetch multiple bags (it considers both lists to be bags). There is an interesting blog post here, and they identify the following solutions: Use @IndexColumn annotation (there is none in my DB, and what's more, I want the position of results to be determined by the ordering, not by an index column) Fetch lazily (for performance reasons, I need eager fetching) Change List to Set So, I changed the List to Set, which by the way is more correct, model-wise. First, if don't use @OrderBy, the PersistentSet returned by Hibernate wraps a HashSet, which has no ordering. Second, If I do use @OrderBy, the PersistentSet wraps a LinkedHashSet, which is what I would like, but the OrderBy property is hardcoded, so all other ordering I perform through the UI comes after it. I tried again with Sets, and used SortedSet (and its implementation, TreeSet), but I have some issues: I want ordering to take place in the DB, and not in-memory, which is what TreeSet does (either through a Comparator, or through the Comparable interface of the elements). Second, I found that there is the Hibernate annotation @Sort, which has a SortOrder.UNSORTED and you can also set a Comparator. I still haven't managed to make it compile, but I am still not convinced it is what I need. Any advice?

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• php cli script hangs with no messages

  - by julio

  Hi-- I've written a PHP script that runs via SSH and nohup, meant to process records from a database and do stuff with them (eg. process some images, update some rows). It works fine with small loads, up to maybe 10k records. I have some larger datasets that process around 40k records (not a lot, I realize, but it adds up to a lot of work when each record requires the download and processing of up to 50 images). The larger datasets can take days to process. Sometimes I'll see in my debug logs memory errors, which are clear enough-- but sometimes the script just appears to "die" or go zombie on me. My tail of the debug log just stops, with no error messages, the tail of the nohup log ends with no error, and the process is still showing in a ps list, looking like this-- 26075 pts/0 S 745:01 /usr/bin/php ./import.php but no work is getting done. Can anyone give me some ideas on why a process would just quit? The obvious things (like a php script timeout and memory issues) are not a factor, as far as I can tell. Thanks for any tips PS-- this is hosted on a godaddy VDS (not my choice). I am sort of suspecting that godaddy has some kind of limits that might kick in on me despite what overrides I put in the code (such as set_time_limit(0);).

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• codingBat separateThousands using regex (and unit testing how-to)

  - by polygenelubricants

  This question is a combination of regex practice and unit testing practice. Regex part I authored this problem separateThousands for personal practice: Given a number as a string, introduce commas to separate thousands. The number may contain an optional minus sign, and an optional decimal part. There will not be any superfluous leading zeroes. Here's my solution: String separateThousands(String s) { return s.replaceAll( String.format("(?:%s)|(?:%s)", "(?<=\\G\\d{3})(?=\\d)", "(?<=^-?\\d{1,3})(?=(?:\\d{3})+(?!\\d))" ), "," ); } The way it works is that it classifies two types of commas, the first, and the rest. In the above regex, the rest subpattern actually appears before the first. A match will always be zero-length, which will be replaceAll with ",". The rest basically looks behind to see if there was a match followed by 3 digits, and looks ahead to see if there's a digit. It's some sort of a chain reaction mechanism triggered by the previous match. The first basically looks behind for ^ anchor, followed by an optional minus sign, and between 1 to 3 digits. The rest of the string from that point must match triplets of digits, followed by a nondigit (which could either be $ or \.). My question for this part is: Can this regex be simplified? Can it be optimized further? Ordering rest before first is deliberate, since first is only needed once No capturing group Unit testing part As I've mentioned, I'm the author of this problem, so I'm also the one responsible for coming up with testcases for them. Here they are: INPUT, OUTPUT "1000", "1,000" "-12345", "-12,345" "-1234567890.1234567890", "-1,234,567,890.1234567890" "123.456", "123.456" ".666666", ".666666" "0", "0" "123456789", "123,456,789" "1234.5678", "1,234.5678" "-55555.55555", "-55,555.55555" "0.123456789", "0.123456789" "123456.789", "123,456.789" I haven't had much experience with industrial-strength unit testing, so I'm wondering if others can comment whether this is a good coverage, whether I've missed anything important, etc (I can always add more tests if there's a scenario I've missed).

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• Caching a column in a polymorphic relationship

  - by Brendon Muir

  I have content management system application that uses a polymorphic tree table as the core of its arrangement. I've come into a problem where once the tree grows quite large, and because we have quite a few different modules (about 25), just doing :include = :instance doesn't cut the mustard. Instance is the name of our polymorphic relationship. The funny part is that in most cases when I want a large list of these items, all I really want is their name from the associated table (for the purposes of an index bar for example), all the rest is in the central table. So I thought that I should probably implement some sort of column cache for the name in the central table. (Like a counter cache that rails already does). I was just wondering if a plugin exists to manage this already? If not, I was just going to add a 'name' column to the central table and because all the polymorphic models inherit off a superclass, just add a callback that pushes the name across to the central table whenever the item is created or updated. I'd then just do a big migration to populate it in the first place? Any flaws to that design? I suppose to be more flexible the column could be some kind of serialised cache where I could store other things later on if need be? Gah! :D

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• Formula parsing / evaluation routine or library with generic DLookup functionality

  - by tbone

  I am writing a .Net application where I must support user-defined formulas that can perform basic mathematics, as well as accessing data from any arbitrary table in the database. I have the math part working, using JScript Eval(). What I haven't decided on is what a nice way is to do the generic table lookups. For example, I may have a formula something like: Column: BonusAmount Formula: {CurrentSalary} * 1.5 * {[SystemSettings][Value][SettingName=CorpBonus AND Year={Year}]} So, in this example I would replace {xxx} and {Year} with the value of Column xxx from the current table, and I would replace the second part with the value of (select Value from SystemSettings WHERE SettingName='CorpBonus' AND Year=2008) So, basically, I am looking for something very much like the MS Access DLookup function: DLookup ( expression, domain, [criteria] ) DLookup("[UnitPrice]", "Order Details", "OrderID = 10248") But, I also need to overall parsing routine that can tell whether to just look up in the current row, or to look into another table. Would also be nice to support aggregate functions (ie: DAvg, DMax, etc), as well as all the weird edge cases handled. So I wonder if anyone knows of any sort of an existing library, or has a nice routine that can handle this formula parsing and database lookup / aggregate function resolution requirements.

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• How to use SerialPort SerialDataReceived help

  - by devnet247

  Hi Not sure how to handle SerialPort DataReceived. Scenario I have an application that communicate with a device and this device returns a status .This happens in different stages EG public enum ActionState { Started, InProgress, Completed etc... } Now if I were to use the DataReceivedEventHandler how can I tell what Method is executing? eg Action1 or Action2 etc...? I also want to include some sort of timeout when getting back stuff from device. Any example or advice? public ActionState Action1 { serialPort.write(myData); string result=serialPort.ReadExisting()); //convertTo ActionState and return return ConvertToActionState(result); } public ActionState Action2 { serialPort.write(myData); string result=serialPort.ReadExisting()); //convertTo ActionState and return return ConvertToActionState(result); } private void port_DataReceived(object sender, SerialDataReceivedEventArgs e) { //How can I use this to detect which method is firing and set the actionState Enum accordingly? } private ActionState(string result) { if(result==1) return ActionState.Started; else if (result==2) return ActionState.Completed etc... }

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• Which knowledge base/rule-based inference engine to choose for real time Runway incursion prevention

  - by Piligrim

  Hello, we are designing a project that would listen to dialog between airport controllers and pilots to prevent runway incursions (eg. one airplane is taking off while other is crossing the runway). Our professor wants us to use Jena for knowledge base (or anything else but it should be some sort of rule-based engine). Inference is not the main thing in Jena and there's not much documentation and examples of this. So we need an engine that would get messages from pilots as input and output possible risks of incursion or any other error in message protocol. It should be easy to write rules, and should be easy to provide engine with real time data. I image it something like this: A pilot sends a message that he lands on some runway, the system remembers that the runway is busy and no one should cross it If someone is given an instruction to cross this runway, the engine should fire a rule that something is wrong When the pilot sends a message that he left the runway and goes to the gate, the system clears the runway and lets other planes to use it. So is Jena, or prolog or any other rules engine suitable for this? I mean it is suitable, but do we really need to use it? I asked the prof. if we could just keep state of the runway and use some simple checks based on messages we receive and he said that it is not scalable and we need the knowledge base. Can someone give me any advise on which approach to use for this system? If you recommend k.b., then which one should we use? The project is written in java. Thank you.

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• Asp.Net MVC 2: How exactly does a view model bind back to the model upon post back?

  - by Dr. Zim

  Sorry for the length, but a picture is worth 1000 words: In ASP.NET MVC 2, the input form field "name" attribute must contain exactly the syntax below that you would use to reference the object in C# in order to bind it back to the object upon post back. That said, if you have an object like the following where it contains multiple Orders having multiple OrderLines, the names would look and work well like this (case sensitive): This works: Order[0].id Order[0].orderDate Order[0].Customer.name Order[0].Customer.Address Order[0].OrderLine[0].itemID // first order line Order[0].OrderLine[0].description Order[0].OrderLine[0].qty Order[0].OrderLine[0].price Order[0].OrderLine[1].itemID // second order line, same names Order[0].OrderLine[1].description Order[0].OrderLine[1].qty Order[0].OrderLine[1].price However we want to add order lines and remove order lines at the client browser. Apparently, the indexes must start at zero and contain every consecutive index number to N. The black belt ninja Phil Haack's blog entry here explains how to remove the [0] index, have duplicate names, and let MVC auto-enumerate duplicate names with the [0] notation. However, I have failed to get this to bind back using a nested object: This fails: Order.id // Duplicate names should enumerate at 0 .. N Order.orderDate Order.Customer.name Order.Customer.Address Order.OrderLine.itemID // And likewise for nested properties? Order.OrderLine.description Order.OrderLine.qty Order.OrderLine.price Order.OrderLine.itemID Order.OrderLine.description Order.OrderLine.qty Order.OrderLine.price I haven't found any advice out there yet that describes how this works for binding back nested ViewModels on post. Any links to existing code examples or strict examples on the exact names necessary to do nested binding with ILists? Steve Sanderson has code that does this sort of thing here, but we cannot seem to get this to bind back to nested objects. Anything not having the [0]..[n] AND being consecutive in numbering simply drops off of the return object. Any ideas?

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• How do I DRY up my CouchDB views?

  - by James A. Rosen

  What can I do to share code among views in CouchDB? Example 1 -- utility methods Jesse Hallett has some good utility methods, including function dot(attr) { return function(obj) { return obj[attr]; } } Array.prototype.map = function(func) { var i, r = [], for (i = 0; i < this.length; i += 1) { r[i] = func(this[i]); } return r; }; ... Where can I put this code so every view can access it? Example 2 -- constants Similarly for constants I use in my application. Where do I put MyApp = { A_CONSTANT = "..."; ANOTHER_CONSTANT = "..."; }; Example 3 -- filter of a filter: What if I want a one view that filters by "is this a rich person?": function(doc) { if (doc.type == 'person' && doc.net_worth > 1000000) { emit(doc.id, doc); } } and another that indexes by last name: function(doc) { if (doc.last_name) { emit(doc.last_name, doc); } } How can I combine them into a "rich people by last name" view? I sort of want the equivalent of the Ruby my_array.select { |x| x.person? }.select { |x| x.net_worth > 1,000,000 }.map { |x| [x.last_name, x] } How can I be DRYer?

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• Google Analytics API Authentication Speedup

  - by Paulo

  I'm using a Google Analytics API Class in PHP made by Doug Tan to retrieve Analytics data from a specific profile. Check the url here: http://code.google.com/intl/nl/apis/analytics/docs/gdata/gdataArticlesCode.html When you create a new instance of the class you can add the profile id, your google account + password, a daterange and whatever dimensions and metrics you want to pick up from analytics. For example i want to see how many people visited my website from different country's in 2009. //make a new instance from the class $ga = new GoogleAnalytics($email,$password); //website profile example id $ga->setProfile('ga:4329539'); //date range $ga->setDateRange('2010-02-01','2010-03-08'); //array to receive data from metrics and dimensions $array = $ga->getReport( array('dimensions'=>('ga:country'), 'metrics'=>('ga:visits'), 'sort'=>'-ga:visits' ) ); Now you know how this API class works, i'd like to adress my problem. Speed. It takes alot of time to retrieve multiple types of data from the analytics database, especially if you're building different arrays with different metrics/dimensions. How can i speed up this process? Is it possible to store all the possible data in a cache so i am able to retrieve the data without loading it over and over again?

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• How to code a URL shortener?

  - by marco92w

  I want to create a URL shortener service where you can write a long URL into an input field and the service shortens the URL to "http://www.example.org/abcdef". Instead of "abcdef" there can be any other string with six characters containing a-z, A-Z and 0-9. That makes 56 trillion possible strings. My approach: I have a database table with three columns: id, integer, auto-increment long, string, the long URL the user entered short, string, the shortened URL (or just the six characters) I would then insert the long URL into the table. Then I would select the auto-increment value for "id" and build a hash of it. This hash should then be inserted as "short". But what sort of hash should I build? Hash algorithms like MD5 create too long strings. I don't use these algorithms, I think. A self-built algorithm will work, too. My idea: For "http://www.google.de/" I get the auto-increment id 239472. Then I do the following steps: short = ''; if divisible by 2, add "a"+the result to short if divisible by 3, add "b"+the result to short ... until I have divisors for a-z and A-Z. That could be repeated until the number isn't divisible any more. Do you think this is a good approach? Do you have a better idea?

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• Sorting ArrayList - IndexOutOfBoundsException -Java

  - by FILIaS

  I'm trying to sort an ArrayList with strings(PlayersNames) and imageIcons(PlayersIcons) based on the values i store in an other arrayList with integers(results). As you can see i get an indexOutOfBoundsException but i cant understand why. Maybe the earling of the morning makes me not to see plain things. ArrayList<String> PlayersNames=new ArrayList<String>; ArrayList<ImageIcon> PlayersIcons=new ArrayList<ImageIcons>; public void sortPlayers(ArrayList<Integer> results){ String tmp; ImageIcon tmp2; for (int i=0; i<PlayersNames.size(); i++) { for (int j=PlayersNames.size(); j>i; j--) { if (results.get(i) < results.get(i+1) ) { //IndexOutOfBoundsException! tmp=PlayersNames.get(i+1); PlayersNames.set(i+1,PlayersNames.get(i)); PlayersNames.set(i,tmp); tmp2=PlayersIcons.get(i+1); PlayersIcons.set(i+1,PlayersIcons.get(i)); PlayersIcons.set(i,tmp2); } } } }

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