Search Results

Search found 9254 results on 371 pages for 'approach'.

Page 76/371 | < Previous Page | 72 73 74 75 76 77 78 79 80 81 82 83  | Next Page >

• How to determine the (natural) language of a document?

  - by Robert Petermeier

  I have a set of documents in two languages: English and German. There is no usable meta information about these documents, a program can look at the content only. Based on that, the program has to decide which of the two languages the document is written in. Is there any "standard" algorithm for this problem that can be implemented in a few hours' time? Or alternatively, a free .NET library or toolkit that can do this? I know about LingPipe, but it is Java Not free for "semi-commercial" usage This problem seems to be surprisingly hard. I checked out the Google AJAX Language API (which I found by searching this site first), but it was ridiculously bad. For six web pages in German to which I pointed it only one guess was correct. The other guesses were Swedish, English, Danish and French... A simple approach I came up with is to use a list of stop words. My app already uses such a list for German documents in order to analyze them with Lucene.Net. If my app scans the documents for occurrences of stop words from either language the one with more occurrences would win. A very naive approach, to be sure, but it might be good enough. Unfortunately I don't have the time to become an expert at natural-language processing, although it is an intriguing topic.

  Read the article

• RESTful idempotence

  - by DutrowLLC

  I'm designing a RESTful web service utilizing ROA(Resource oriented architecture). I'm trying to work out an efficient way to guarantee idempotence for PUT requests that create new resources in cases that the server designates the resource key. From my understanding, the traditional approach is to create a type of transaction resource such as /CREATE_PERSON. The the client-server interaction for creating a new person resource would be in two parts: Step 1: Get unique transaction id for creating the new PERSON resource::: **Client request:** GET /CREATE_PERSON **Server response:** 200 OK transaction-id:"as8yfasiob" Step 2: Create the new person resource in a request guaranteed to be unique by using the transaction id::: **Client request** PUT /CREATE_PERSON/{transaction_id} first_name="Big bubba" **Server response** 201 Created // (If the request is a duplicate, it would send this PersonKey="398u4nsdf" // same response without creating a new resource. It // would perhaps send an error response if the was used // on a transaction id non-duplicate request, but I have // control over the client, so I can guarantee that this // won't happen) The problem that I see with this approach is that it requires sending two requests to the server in order to do to single operation of creating a new PERSON resource. This creates a performance issues increasing the chance that the user will be waiting around for the client to complete their request. I've been trying to hash out ideas for eliminating the first step such as pre-sending transaction-id's with each request, but most of my ideas have other issues or involve sacrificing the statelessness of the application. Is there a way to do this?

  Read the article

• When writing a game, should you make objects/enemies/etc. have unique ID numbers?

  - by SLC

  I have recently encountered some issues with merely passing references to objects/enemies in a game I am making, and am wondering if I am using the wrong approach. The main issue I have is disposing of enemies and objects, when other enemies or players may still have links to them. For example, if you have a Rabbit, and a Wolf, the Wolf may have selected the Rabbit to be its target. What I am doing, is the wolf has a GameObject Target = null; and when it decides it is hungry, the Target becomes the Rabbit. If the Rabbit then dies, such as another wolf killing it, it cannot be removed from the game properly because this wolf still has a reference to it. In addition, if you are using a decoupled approach, the rabbit could hit by lightning, reducing its health to below zero. When it next updates itself, it realises it has died, and is removed from the game... but there is no way to update everything that is interested in it. If you gave every enemy a unique ID, you could simply use references to that instead, and use a central lookup class that handled it. If the monster died, the lookup class could remove it from its own index, and subsequently anything trying to access it would be informed that it's dead, and then they could act accordingly. Any thoughts on this?

  Read the article

• Can a WCF Service provide publish/subscribe activity to a Linux-based C++ client application?

  - by Jeremy Roddingham

  I have a WCF service written to provide certain functionality to intranet-based clients. This is easy when a client is running Windows. I want to implement the same functionality for my Windows clients that is available to my linux clients. My questions are? How can I communicate to a linux c++ based client (supporting callback operations for a publish subscribe) type situation? I am aware of using SOAP over the HTTPBinding but is that the only way (does not support callbacks I believe)? Would the same apply if I were using TCPBinding on the service-side? Currently, the service is set up using TCP but what are my options for the linux client communcation? I read somewhere that messages can also be sent (via webservices I believe) in XML rather than SOAP? Which would be a better approach or how to determine which is a better approach? I am trying to understand the options I would have for a WCF data service if I wanted to communicate with it from a linux client. I appreciate all your help. Thank You, Jeremy

  Read the article

• Using IsolatedStorage on a IIS server

  - by JoeBilly

  I'am a bit confusing about the use of Isolated Storage on an IIS server. I understand the goal of Isolated Storage : provides a safe place to store data with no worry about how and where is this place. Since Isolated Storage has a by-user and by-assembly approach, I'am not to wild about using it on a IIS server where applications have almost their own identity. I haven't really seen the interest of impersonating a web application and almost never seen impersonated web applications myself but this is my point of view. Using Isolated Storage on a server mean : Using Isolated stores in \Documents and Settings\<user>\ Which mean \Documents and Settings\Default User\ when the application pool is owned by Local System or Network Services I guess Which also mean Write rights on this folder for Local System or Network Services Using of impersonation Regarding a web application (logic), these ideas are confusing me... Document and Settings ? Default User ? Enable impersonation just for storage ? No control about storage on server ? Uh ? And then I'am a front of a dilema : use System.IO.Packaging (with Isolated Storage inside) on web applications or find an alternative ? Am I wrong in my approach ? Did I miss something ? Any point of view is appreciated and an explanation about the Isolated Storage with IIS philosophy could be an anwser. Thanks !

  Read the article

• Feasibility of using Silverlight for web and windows client with common code base for data intensive

  - by Kabeer

  Hello. Recently in a conversation, someone suggested me to make use of Silverlight if I am targeting a web client and a windows client for the same application. This will cut down my effort for supporting the contrast in both presentation layers. Mine is a product, that will be deployed in enterprises. Both web and windows clients are desirable. With the above context, I have few queries: Is it advisable to adopt the recommended approach and whether this approach is becoming a trend? Besides, some configuration & deployment tweaking, will this significantly reduce effort on the presentation layer? Is there a possibility that my future prospects (for this product) will resist Silverlight footprint? Will I be able to make use of the ASP.Net MVC pattern? Will there be any performance implication for the web client? Will Silverlight support incremental load of controls? If my back-end includes SSRS, will I be able to harness all its front end features with Silverlight? Will I be able to support additional devices with same code base in future? Mine is a very data intensive application from both, data entry and reporting perspective. Is it advisable to use 3rd party controls (like Telerik) for improved user experience and developer productivity? Are their any professional quality open source Silverlight controls (library) available? Further, I seek information of best practices in the context I shared above.

  Read the article

• Forcing CLLocationManager updates - does it help or hurt?

  - by Steve N

  I've been trying to find any way to optimize the performance of my location-based iPhone application and have seen some people mention that you can force location updates by starting and stopping your CLLocationManager. I need the best accuracy I can get, and the user in my case would probably like to see updates every few seconds (say, 10 seconds) as they walk around. I've set the filters accordingly, but I notice that sometimes I don't get any updates on the device for quite some time. I'm testing the following approach, which forces an update when a fixed time interval passes (I'm using 20 seconds). My gut tells me this really won't help me provide more accurate updates to the user, and that just leaving CLLocationManager running all the time is probably the best approach. - (void)forceLocationUpdate { [[LocationManager locationManager] stopUpdates]; [[LocationManager locationManager] startUpdates]; [self performSelector:@selector(forceLocationUpdate) withObject:nil afterDelay:20.0]; } My question is- does forcing updates from CLLocationManager actually improve core location performance? Does it hurt performance? If I'm outside in an open field with good GPS reception, will this help then? Does anyone have experience trying this? Thanks in advance, Steve

  Read the article

• BackgroundWorker From ASP.Net Application

  - by Kevin

  We have an ASP.Net application that provides administrators to work with and perform operations on large sets of records. For example, we have a "Polish Data" task that an administrator can perform to clean up data for a record (e.g. reformat phone numbers, social security numbers, etc.) When performed on a small number of records, the task completes relatively quickly. However, when a user performs the task on a larger set of records, the task may take several minutes or longer to complete. So, we want to implement these kinds of tasks using some kind of asynchronous pattern. For example, we want to be able to launch the task, and then use AJAX polling to provide a progress bar and status information. I have been looking into using the BackgroundWorker class, but I have read some things online that make me pause. I would love to get some additional advice on this. For example, I understand that the BackgroundWorker will actually use the thread pool from the current application. In my case, the application is an ASP.Net web site. I have read that this can be a problem because when the application recycles, the background workers will be terminated. Some of the jobs I mentioned above may take 3 minutes, but others may take a few hours. Also, we may have several hundred administrators all performing similar operations during the day. Will the ASP.Net application thread pool be able to handle all of these background jobs efficiently while still performing it's normal request processing? So, I am trying to determine if using the BackgroundWorker class and approach is right for our needs. Should I be looking at an alternative approach? Thanks and sorry for such a long post! Kevin

  Read the article

• How do you invoke a python script inside a jar file using python ?

  - by Trevor

  I'm working on an application that intersperses a bunch of jython and java code. Due to the nature of the program (using wsadmin) we are really restricted to Python 2.1 We currently have a jar containing both java source and .py modules. The code is currently invoked using java, but I'd like to remove this in favor of migrating as much functionality as possible to jython. The problem I have is that I want to either import or execute python modules inside the existing jar file from a calling jython script. I've tried a couple of different ways without success. My directory structure looks like: application.jar |-- com |--example |-- action |-- MyAction.class |-- pre_myAction.py The 1st approach I tried was to do imports from the jar. I added the jar to my sys.path and tried to import the module using both import com.example.action.myAction and import myAction. No success however, even when I put init.py files into the directory at each level. The 2nd approach I tried was to load the resource using the java class. So I wrote the below code: import sys import os import com.example.action.MyAction as MyAction scriptName = str(MyAction.getResource('/com/example/action/myAction.py')) scriptStr = MyAction.getResourceAsStream('/com/example/action/myAction.py') try: print execfile(scriptStr) except: print "failed 1" try: print execfile(scriptName) except: print "failed 2" Both of these failed. I'm at a bit of a loss now as to how I should proceed. Any ideas ? cheers, Trevor

  Read the article

• How to setup prawn on heroku when installed as a git submodule

  - by brad

  I have a rails app that I am trying to deploy to heroku. This app generates pdfs using prawn. I installed prawn as a git submodule rather than as a gem as this is what is recommended on the prawn website (here). This has not worked well with heroku so far though. As stated on heroku's application constraints page submodules are not supported so I followed their instructions to track the submodule in the main project and tried again. This has not worked and when I access my application I get the following error: App failed to start An error happened during the initialization of your app. This may be due to a typo, wrong number of arguments, or calling a function that doesn’t exists. Check the stack trace below for specific details. Make sure the app is working locally in production mode, by running it with RAILS_ENV (for Rails apps) or RACK_ENV (for Sinatra or other rack apps) set to production. e.g. RAILS_ENV=production script/server. Original Error /usr/local/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require': /disk1/home/slugs/208590_03c9c22_67f5/mnt/app/controllers/invoices_controller.rb:37: syntax error, unexpected ')' (SyntaxError) ).to_pdf(@invoice) (and then a whole lot more that I'll spare you from) The .to_pdf function described in the last line is called in a controller in exactly the way described in the prawn how-to that I linked to above so my interpretation of the error message is that prawn is not being installed/detected. Does anyone know how I can address this? I'm new to heroku so have little idea how to approach this. Is the submodule approach for prawn dead in the water from the get-go? Do I need to install it as a gem instead. I'd rather keep it as a submodule just because that works for now and I don't want to break it.

  Read the article

• 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?

  Read the article

• Is SQLDataReader slower than using the command line utility sqlcmd?

  - by Andrew

  I was recently advocating to a colleague that we replace some C# code that uses the sqlcmd command line utility with a SqlDataReader. The old code uses: System.Diagnostics.ProcessStartInfo procStartInfo = new System.Diagnostics.ProcessStartInfo("cmd", "/c " + sqlCmd); wher sqlCmd is something like "sqlcmd -S " + serverName + " -y 0 -h-1 -Q " + "\"" + "USE [" + database + "]" + ";+ txtQuery.Text +"\"";\ The results are then parsed using regular expressions. I argued that using a SQLDataReader woud be more in line with industry practices, easier to debug and maintain and probably faster. However, the SQLDataReader approach is at least the same speed and quite possibly slower. I believe I'm doing everything correctly with SQLDataReader. The code is: using (SqlConnection connection = new SqlConnection()) { try { SqlConnectionStringBuilder builder = new SqlConnectionStringBuilder(connectionString); connection.ConnectionString = builder.ToString(); ; SqlCommand command = new SqlCommand(queryString, connection); connection.Open(); SqlDataReader reader = command.ExecuteReader(); // do stuff w/ reader reader.Close(); } catch (Exception ex) { outputMessage += (ex.Message); } } I've used System.Diagnostics.Stopwatch to time both approaches and the command line utility (called from C# code) does seem faster (20-40%?). The SqlDataReader has the neat feature that when the same code is called again, it's lightening fast, but for this application we don't anticipate that. I have already done some research on this problem. I note that the command line utility sqlcmd uses OLE DB technology to hit the database. Is that faster than ADO.NET? I'm really suprised, especially since the command line utility approach involves starting up a process. I really thought it would be slower. Any thoughts? Thanks, Dave

  Read the article

• PHP XML Strategy: Parsing DOM to fill "Bean"

  - by Mike

  I have a question concerning a good strategy on how to fill a data "bean" with data inside an xml file. The bean might look like this: class Person { var $id; var $forename = ""; var $surname = ""; var $bio = new Biography(); } class Biography { var $url = ""; var $id; } the xml subtree containing the info might look like this: <root> <!-- some more parent elements before node(s) of interest --> <person> <name pre="forename"> Foo </name> <name pre="surname"> Bar </name> <id> 1254 </id> <biography> <url> http://www.someurl.com </url> <id> 5488 </id> </biography> </person> </root> At the moment, I have one approach using DOMDocument. A method iterates over the entries and fills the bean by "remembering" the last node. I think thats not a good approach. What I have in mind is something like preconstructing some xpath expression(s) and then iterate over the subtrees/nodeLists. Return an array containing the beans as defined above eventually. However, it seems not to be possible reusing a subtree /DOMNode as DOMXPath constructor parameter. Has anyone of you encountered such a problem?

  Read the article

• How should I implement reverse AJAX in a Django application?

  - by Carson Myers

  How should I implement reverse AJAX when building a chat application in Django? I've looked at Django-Orbited, and from my understanding, this puts a comet server in front of the HTTP server. This seems fine if I'm just running the Django development server, but how does this work when I start running the application from mod_wsgi? How does having the orbited server handling every request scale? Is this the correct approach? I've looked at another approach (long polling) that seems like it would work, although I'm not sure what all would be involved. Would the client request a page that would live in its own thread, so as not to block the rest of the application? Would it even block? Wouldn't the script requested by the client have to continuously poll for information? Which of the approaches is more proper? Which is more portable, scalable, sane, etc? Are there other good approaches to this (aside from the client polling for messages) that I have overlooked?

  Read the article

• detecting pauses in a spoken word audio file using pymad, pcm, vad, etc

  - by james

  First I am going to broadly state what I'm trying to do and ask for advice. Then I will explain my current approach and ask for answers to my current problems. Problem I have an MP3 file of a person speaking. I'd like to split it up into segments roughly corresponding to a sentence or phrase. (I'd do it manually, but we are talking hours of data.) If you have advice on how to do this programatically or for some existing utilities, I'd love to hear it. (I'm aware of voice activity detection and I've looked into it a bit, but I didn't see any freely available utilities.) Current Approach I thought the simplest thing would be to scan the MP3 at certain intervals and identify places where the average volume was below some threshold. Then I would use some existing utility to cut up the mp3 at those locations. I've been playing around with pymad and I believe that I've successfully extracted the PCM (pulse code modulation) data for each frame of the mp3. Now I am stuck because I can't really seem to wrap my head around how the PCM data translates to relative volume. I'm also aware of other complicating factors like multiple channels, big endian vs little, etc. Advice on how to map a group of pcm samples to relative volume would be key. Thanks!

  Read the article

• Linq to find pair of points with longest length?

  - by Chris

  I have the following code: foreach (Tuple<Point, Point> pair in pointsCollection) { var points = new List<Point>() { pair.Value1, pair.Value2 }; } Within this foreach, I would like to be able to determine which pair of points has the most significant length between the coordinates for each point within the pair. So, let's say that points are made up of the following pairs: (1) var points = new List<Point>() { new Point(0,100), new Point(100,100) }; (2) var points = new List<Point>() { new Point(150,100), new Point(200,100) }; So I have two sets of pairs, mentioned above. They both will plot a horizontal line. I am interested in knowing what the best approach would be to find the pair of points that have the greatest distance between, them, whether it is vertically or horizontally. In the two examples above, the first pair of points has a difference of 100 between the X coordinate, so that would be the point with the most significant difference. But if I have a collection of pairs of points, where some points will plot a vertical line, some points will plot a horizontal line, what would be the best approach for retrieving the pair from the set of points whose difference, again vertically or horizontally, is the greatest among all of the points in the collection? Thanks! Chris

  Read the article

• Optimized Publish/Subcribe JMS Broker Cluster and Conflicting Posts on StackOverFlow for the Answer

  - by Gene

  Hi, I am looking to build a publish/subscribe distributed messaging framework that can manage huge volumes of message traffic with some intelligence at the broker level. I don't know if there's a topology that describes this, but this is the model I'm going after: EXAMPLE MODEL A A) There are two running message brokers (ideally all on localhost if possible, for easier demo-ing) : Broker-A Broker-B B) Each broker will have 2 listeners and 1 publisher. Example Figure [subscriber A1, subscriber A2, publisher A1] <-- BrokerA <-- BrokerB <-- [publisher B1, subscriber B1, subscriber B2] IF a message-X is published to broker A and there no subscribers for it among the listeners on Broker-B (via criteria in Message Selectors or Broker routing rules), then that message-X will never be published to Broker-B. ELSE, broker A will publish the message to broker B, where one of the broker B listeners/subscribers/services is expecting that message based on the subscription criteria. Is Clustering the Correct Approach? At first, I concluded that the "Broker Clustering" concept is what I needed to support this. However, as I have come to understand it, the typical use of clustering entails either: message redundancy across all brokers ... or Competing Consumers pattern ... and neither of these satisfy the requirement in the EXAMPLE MODEL A. What is the Correct Approach? My question is, does anyone know of a JMS implementation that supports the model I described? I scanned through all the stackoverflow post titles for the search: JMS and Cluster. I found these two informative, but seemingly conflicting posts: Says the EXAMPLE MODEL A is/should-be implicitly supported: http://stackoverflow.com/questions/2255816/jms-consumer-with-activemq-network-of-brokers " this means you pick a broker, connect to it, and let the broker network sort it out amongst themselves. In theory." Says the EXAMPLE MODEL A IS NOT suported: http://stackoverflow.com/questions/2017520/how-does-a-jms-topic-subscriber-in-a-clustered-application-server-recieve-message "All the instances of PropertiesSubscriber running on different app servers WILL get that message." Any suggestions would be greatly appreciated. Thanks very much for reading my post, Gene

  Read the article

• GAE python database object design for simple list of values

  - by Joey

  I'm really new to database object design so please forgive any weirdness in my question. Basically, I am use Google AppEngine (Python) and contructing an object to track user info. One of these pieces of data is 40 Achievement scores. Do I make a list of ints in the User object for this? Or do I make a separate entity with my user id, the achievement index (0-39) and the score and then do a query to grab these 40 items every time I want to get the user data in total? The latter approach seems more object oriented to me, and certainly better if I extend it to have more than just scores for these 40 achievements. However, considering that I might not extend it, should I even consider just doing a simple list of 40 ints in my user data? I would then forgo doing a query, getting the sorted list of achievements, reading the score from each one just to process a response etc. Is doing this latter approach just such a common practice and hand-waved as not even worth batting an eyelash at in terms of thinking it might be more costly or complex processing wise?

  Read the article

• "Public" nested classes or not

  - by Frederick

  Suppose I have a class 'Application'. In order to be initialised it takes certain settings in the constructor. Let's also assume that the number of settings is so many that it's compelling to place them in a class of their own. Compare the following two implementations of this scenario. Implementation 1: class Application { Application(ApplicationSettings settings) { //Do initialisation here } } class ApplicationSettings { //Settings related methods and properties here } Implementation 2: class Application { Application(Application.Settings settings) { //Do initialisation here } class Settings { //Settings related methods and properties here } } To me, the second approach is very much preferable. It is more readable because it strongly emphasises the relation between the two classes. When I write code to instantiate Application class anywhere, the second approach is going to look prettier. Now just imagine the Settings class itself in turn had some similarly "related" class and that class in turn did so too. Go only three such levels and the class naming gets out out of hand in the 'non-nested' case. If you nest, however, things still stay elegant. Despite the above, I've read people saying on StackOverflow that nested classes are justified only if they're not visible to the outside world; that is if they are used only for the internal implementation of the containing class. The commonly cited objection is bloating the size of containing class's source file, but partial classes is the perfect solution for that problem. My question is, why are we wary of the "publicly exposed" use of nested classes? Are there any other arguments against such use?

  Read the article

• Programmer Puzzle: Encoding a chess board state throughout a game

  - by Andrew Rollings

  Not strictly a question, more of a puzzle... Over the years, I've been involved in a few technical interviews of new employees. Other than asking the standard "do you know X technology" questions, I've also tried to get a feel for how they approach problems. Typically, I'd send them the question by email the day before the interview, and expect them to come up with a solution by the following day. Often the results would be quite interesting - wrong, but interesting - and the person would still get my recommendation if they could explain why they took a particular approach. So I thought I'd throw one of my questions out there for the Stack Overflow audience. Question: What is the most space-efficient way you can think of to encode the state of a chess game (or subset thereof)? That is, given a chess board with the pieces arranged legally, encode both this initial state and all subsequent legal moves taken by the players in the game. No code required for the answer, just a description of the algorithm you would use. EDIT: As one of the posters has pointed out, I didn't consider the time interval between moves. Feel free to account for that too as an optional extra :) EDIT2: Just for additional clarification... Remember, the encoder/decoder is rule-aware. The only things that really need to be stored are the player's choices - anything else can be assumed to be known by the encoder/decoder. EDIT3: It's going to be difficult to pick a winner here :) Lots of great answers!

  Read the article

• Retrieving many huge sized EPS files and converting them to JPEG in ASP.NET application

  - by Ashish Gupta

  I have many (600) EPS files(300 KB - 1 MB) in database. In my ASP.NET application (using ASP.NET 4.0) I need to retrieve them one by one and call a web service which would convert the content to the JPEG file and update the database (JPEGContent column with the JPEG content). However, retrieving the content for 600 of them itself takes too long from the SQL management studio itself (takes 5 minutes for 10 EPS contents). So I have two issues:- 1) How to get the EPS content ( unfortunately, selecting certain number of content is not an option :-( ):- Approach 1:- foreach(var DataRow in DataTable.Rows) { // get the Id and byte[] of EPS // Call the web method to convert EPS content to JPEG which would also update the database. } or foreach(var DataRow in DataTable.Rows) { // get only the Id of EPS // Hit database to get the content of EPS // Call the web method to convert EPS content to JPEG which would also update the database. } or Any other approach? 2) Converting EPS to JPEG using a web method for 600 contents. Ofcourse, each call would be a long running operation. Would task parellel library (TPL) be a better way to achieve this? Also, is doing the entire thing in a SQL CLR function a good idea?

  Read the article

• how can I add a custom non-DataTable column to my DataView, in a winforms ADO.net application?

  - by Greg

  Hi, How could I (/is it possible) to add a custom column to my DataView, and in this column display the result of a specific calculation. That is, I currently have a dataGridView which has a binding to a DataView, based on the DataTable from my database. I'd like to add an additional column to the dataGridView to display a number which is calculated by looking at this current row plus it's children row. In other words the info for the column isn't just derivable from the row data itself. Specific questions might be: a) where to add the column itself? to the DataView I assume? b) which method / event to trigger the re-calculation of the value of this custom column from ( / how do I control this) Thanks PS. I've also noted if I use the following code/approach I get a infinite loop... // Custom Items DataColumn dc = new DataColumn("OverallSize", typeof(long)); DT_Webfiles.Columns.Add(dc); DT_Webfiles.RowChanged += new DataRowChangeEventHandler(DT_Row_Changed); private static void DT_Row_Changed(object sender, DataRowChangeEventArgs e) { e.Row["OverallSize"] = e.Row["OverallSize"] ?? 0; e.Row["OverallSize"] = (long)e.Row["OverallSize"] + 1; } What other approach could avoid this looping. i.e. currently I'm saying update the value of the custom column when the row changes, however after then changing the row it triggers antoher 'row has changed' event...

  Read the article

• Refactoring ADO.NET - SqlTransaction vs. TransactionScope

  - by marc_s

  I have "inherited" a little C# method that creates an ADO.NET SqlCommand object and loops over a list of items to be saved to the database (SQL Server 2005). Right now, the traditional SqlConnection/SqlCommand approach is used, and to make sure everything works, the two steps (delete old entries, then insert new ones) are wrapped into an ADO.NET SqlTransaction. using (SqlConnection _con = new SqlConnection(_connectionString)) { using (SqlTransaction _tran = _con.BeginTransaction()) { try { SqlCommand _deleteOld = new SqlCommand(......., _con); _deleteOld.Transaction = _tran; _deleteOld.Parameters.AddWithValue("@ID", 5); _con.Open(); _deleteOld.ExecuteNonQuery(); SqlCommand _insertCmd = new SqlCommand(......, _con); _insertCmd.Transaction = _tran; // add parameters to _insertCmd foreach (Item item in listOfItem) { _insertCmd.ExecuteNonQuery(); } _tran.Commit(); _con.Close(); } catch (Exception ex) { // log exception _tran.Rollback(); throw; } } } Now, I've been reading a lot about the .NET TransactionScope class lately, and I was wondering, what's the preferred approach here? Would I gain anything (readibility, speed, reliability) by switching to using using (TransactionScope _scope = new TransactionScope()) { using (SqlConnection _con = new SqlConnection(_connectionString)) { .... } _scope.Complete(); } What you would prefer, and why? Marc

  Read the article

• Converting python collaborative filtering code to use Map Reduce

  - by Neil Kodner

  Using Python, I'm computing cosine similarity across items. given event data that represents a purchase (user,item), I have a list of all items 'bought' by my users. Given this input data (user,item) X,1 X,2 Y,1 Y,2 Z,2 Z,3 I build a python dictionary {1: ['X','Y'], 2 : ['X','Y','Z'], 3 : ['Z']} From that dictionary, I generate a bought/not bought matrix, also another dictionary(bnb). {1 : [1,1,0], 2 : [1,1,1], 3 : [0,0,1]} From there, I'm computing similarity between (1,2) by calculating cosine between (1,1,0) and (1,1,1), yielding 0.816496 I'm doing this by: items=[1,2,3] for item in items: for sub in items: if sub >= item: #as to not calculate similarity on the inverse sim = coSim( bnb[item], bnb[sub] ) I think the brute force approach is killing me and it only runs slower as the data gets larger. Using my trusty laptop, this calculation runs for hours when dealing with 8500 users and 3500 items. I'm trying to compute similarity for all items in my dict and it's taking longer than I'd like it to. I think this is a good candidate for MapReduce but I'm having trouble 'thinking' in terms of key/value pairs. Alternatively, is the issue with my approach and not necessarily a candidate for Map Reduce?

  Read the article

• Attributes of attributevalue element in SAML 2 Attribute Statement

  - by AJ

  I am building a web service that receives a SAML attribute query and responds with an attribute statement. I know I can return one or multiple values of a SAML attribute. I have some values that are dependent on the other attribute values. I need to show that relationship. Let us say, the query is for the Subject Dave and the return values are his company and job title. Dave can work at multiple companies with job title at each company. I have two options of sending this data back: Send this as a complextype by defining an attribute organization and return xml within that attribute. <saml:Attribute name="company"> <saml:AttributeValue> <company name="company1" jobtitle="CIO"/> <company name="company2" jobtitle="VP"/> </saml:AttributeValue> Try to send multiple values of attributes somehow sending a reference in attributevalue element. <saml:Attribute name="company"> <attributeValue>company1</attributeValue> <attributeValue>company2</attributeValue> </saml:Attribute> <saml:Attribute name="jobTitle> <attributeValue company="company1">CIO</attributeValue> <attributeValue company="company2">VP</attributeValue> </saml:Attribute> Which approach will you prefer? Why? I am biased towards second approach as it does not require client to know about any schema. It does require them to know about non-standard attribute company in the attribute value.

  Read the article

< Previous Page | 72 73 74 75 76 77 78 79 80 81 82 83  | Next Page >