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• PHP - REGEX - use string for pattern but exclude it from being removed!

  - by aSeptik

  Hi All guys! i'm pretty new on regex, i have learned something by the way, but is still pour knowledge! so i want ask you for clarification on how it work! assuming i have the following strings, as you can see they can be formatted little different way one from another but they are very similar! DTSTART;TZID="America/Chicago":20030819T000000 DTEND;TZID="America/Chicago":20030819T010000 DTSTART;TZID=US/Pacific DTSTART;VALUE=DATE now i want replace everything between the first A-Z block and the colon so for example i would keep DTSTART:20030819T000000 DTEND:20030819T010000 DTSTART DTSTART so on my very noobs knowledge i have worked out this shitty regex! :-( preg_replace( '/^[A-Z](?!;[A-Z]=[\w\W]+):$/m' , '' , $data ); but why i'm sure this regex will not work!? :-) Pls help me! PS: the title of question is pretty explaned, i want also know how for example use a well know string block for match another... preg_replace( '/^[DTSTART](?!;[A-Z]=[\w\W]+):$/m' , '' , $data ); ..without delete DTSTART Thanks for the time! Regards Luca Filosofi

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• Aspect-Oriented Programming in OOP world - breaking rules ?

  - by Maksim Kondratyuk

  Hi 2 all! When I worked on asp.net mvc web site project, I investigated different approaches for validation. Some of them were DataAnotation validation and Validation Block. They use attributes for setting up rules for validation. Like this: [Required] public string Name {get;set;} I was confused how this approach combines with SRP (single responsibilty principle) from OOP world. Also I don't like any business logic in business objects, I prefer "poor business objects" model, but when I decorate my business objects with validation attributes for real requirements, they become ugly (Has a lot of attributes / with localization logic and so on). Idea with attributes realy simple, but in my opinion the validation decoration should be separated from object. I'm not sure is the approach to separate validation rules to xml files or to another objects, maybe it is a solution. Another bad side of AOP - problems with unit testin such code. When I decorated some controller actions with custom attributes for example to import/export TempData between actions or initialize some required services I can't to write proper unit test for testing this actions. Do you think that attributes don't break srp or you just disregard this and think that it's simplest , is not worst way ? P.S. I read some likes articles and discussions and I just want to put things in proper order. P.P.S. sorry for my "fluent" english :=)

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• Save PyML.classifiers.multi.OneAgainstRest(SVM()) object?

  - by Michael Aaron Safyan

  I'm using PYML to construct a multiclass linear support vector machine (SVM). After training the SVM, I would like to be able to save the classifier, so that on subsequent runs I can use the classifier right away without retraining. Unfortunately, the .save() function is not implemented for that classifier, and attempting to pickle it (both with standard pickle and cPickle) yield the following error message: pickle.PicklingError: Can't pickle : it's not found as __builtin__.PySwigObject Does anyone know of a way around this or of an alternative library without this problem? Thanks. Edit/Update I am now training and attempting to save the classifier with the following code: mc = multi.OneAgainstRest(SVM()); mc.train(dataset_pyml,saveSpace=False); for i, classifier in enumerate(mc.classifiers): filename=os.path.join(prefix,labels[i]+".svm"); classifier.save(filename); Notice that I am now saving with the PyML save mechanism rather than with pickling, and that I have passed "saveSpace=False" to the training function. However, I am still gettting an error: ValueError: in order to save a dataset you need to train as: s.train(data, saveSpace = False) However, I am passing saveSpace=False... so, how do I save the classifier(s)? P.S. The project I am using this in is pyimgattr, in case you would like a complete testable example... the program is run with "./pyimgattr.py train"... that will get you this error. Also, a note on version information: [michaelsafyan@codemage /Volumes/Storage/classes/cse559/pyimgattr]$ python Python 2.6.1 (r261:67515, Feb 11 2010, 00:51:29) [GCC 4.2.1 (Apple Inc. build 5646)] on darwin Type "help", "copyright", "credits" or "license" for more information. import PyML print PyML.__version__ 0.7.0

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• Encoding/Decoding hex packet

  - by Roberto Pulvirenti

  I want to send this hex packet: 00 38 60 dc 00 00 04 33 30 3c 00 00 00 20 63 62 39 62 33 61 36 37 34 64 31 36 66 32 31 39 30 64 30 34 30 63 30 39 32 66 34 66 38 38 32 62 00 06 35 2e 31 33 2e 31 00 00 02 3c so i build the string: string packet = "003860dc0000" + textbox1.text+ "00000020" + textbox2.text+ "0006" + textbox3.text; then "convert" it to ascii: conn_str = HexString2Ascii(packet); then i send the packet... but i have this: 00 38 60 **c3 9c** 00 00 04 33 30 3c 00 00 00 20 63 62 39 62 33 61 36 37 34 64 31 36 66 32 31 39 30 64 30 34 30 63 30 39 32 66 34 66 38 38 32 62 00 06 35 2e 31 33 2e 31 00 00 02 3c **0a** why?? Thank you! P.S. the function is: private string HexString2Ascii(string hexString) { byte[] tmp; int j = 0; int lenght; lenght=hexString.Length-2; tmp = new byte[(hexString.Length)/2]; for (int i = 0; i <= lenght; i += 2) { tmp[j] =(byte)Convert.ToChar(Int32.Parse(hexString.Substring(i, 2), System.Globalization.NumberStyles.HexNumber)); j++; } return Encoding.GetEncoding(1252).GetString(tmp); }

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• How to detect a WCF session crash before calling a contract method?

  - by brain_pusher

  I am using a session mode for my WCF service. The problem is the following: if session is broken and no longer exists, client can't know it before calling a contract. For example, if the service has been restarted, the client's session id is invalid, because that session has been closed on the server side. I check the channel state before calling the contract and its value is CommunicationState.Opened even if session is already broken. So, when I call the contract after this check I get a CommunicationException with this message: The remote endpoint no longer recognizes this sequence. This is most likely due to an abort on the remote endpoint. The value of wsrm:Identifier is not a known Sequence identifier. The reliable session was faulted. Is there any workaround? I need a way to get an appropriate session state before calling a contract so that I can restore it without getting an exception. P.S. The CommunicationException type is general, so I can't detect a session crash by catching this exception. P.P.S. I have asked the similar question here, but in that case I didn't know the reason, now I don't know how to evade it.

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• Close TCP connection when owner process is already killed

  - by Otiel

  I have a Windows service that - when it starts - opens some WCF services to listen on the 8000 port. It happens that this service crashes sometimes. When it does, the TCP connection is not released, thus causing my service to throw an exception if I try to start it again: AddressAlreadyInUseException: There is already a listener on IP endpoint 0.0.0.0:8000 Some observations: When running CurrPorts or netstat -ano, I can see that the 8000 port is still in use (in LISTENING state) and is owned by the Process ID XXX that corresponded to my service process ID. But my service has already crashed, and does not appear in the Task Manager anymore. Thus I can't kill the process to free the port! Of course, running taskkill /PID XXX returns: ERROR: The process "XXX" not found. When running CurrPorts or netstat -b, I can see that the process name involved in creating the listening port is System, and not as MyService.exe (whereas it is MyService.exe when my service is running). I tried to use CurrPorts to close the connection, but I always get the following error message: Failed to close one or more TCP connections. Be aware that you must run this tool as admin in order to close TCP connections. (Useless to say, I do run CurrPorts as Administrator...) TCPView is not much help either: the process name associated to the 8000 port is <non-existent>, and doing "End process" or "Close connection" has no effect. I tried to see if there was not a child process associated with the PID XXX using Process Explorer, but no luck here. If I close my service properly (before it crashes), the TCP connection is correctly released. This is normal, as I close the WCF service hosts in the OnStop() event of my service. The only way I found to release the connection is to restart the server (which is not convenient in a production environment as you can guess). Waiting does not help, the TCP connection is never released. How can I close the connection without restarting the Windows server? PS: found some questions extremely similar to mine.

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• Is there a way to easily convert a series of tarballs of a source tree into a git repository?

  - by Hotei

  I'm new to git and I have a moderately large number of weekly tarballs from a long running project. Each tarball has on average a few hundred files in it. I'm looking for a git strategy that will allow me to add the expanded contents of each tarball to a new git repository, starting from version 1.001 and going through version 1.650. As of this stage of the project 99.5% of tarball(n) is just a copy of version(n-1) - in other words, a perfect candidate for git. The desired end result is to have only the master branch remaining at the end of the process. I think I know git well enough to do this "by hand". As I understand it there is no possibility of a merge conflict since there will be no opportunity to change the master before the next version is added and committed. A shell script is my first guess, but I'm not sure how well bash will like it when git checkout branch_n gets processed while bash is executing in branch_n-1. For the purposes of this project the host environment is Ubuntu 10.4, resources available are 8 Gig RAM, 500 Gig Disk space free and 4 CPU processor at 3.ghz . I don't need someone else to solve the problem but I could use a nudge in the right direction as to how a git expert would approach it. Any advice from someone who's "been there done that" would be appreciated. Hotei PS: I have looked at site's suggested "related questions" and found nothing relevant.

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• How to get resultset with stored procedure calls over two linked servers?

  - by räph

  I have problems filling a temporary table with the resultset from a procedure call on a linked server, in which again a procedure on another server is called. I have a Stored Procedure sproc1 with the following code, which calls another procedure sproc2 on a linked server. SET @sqlCommand = 'INSERT INTO #tblTemp ( ModuleID, ParamID) ' + '( SELECT * FROM OPENQUERY(' + @targetServer + ', ' + '''SET FMTONLY OFF; EXEC ' + @targetDB + '.usr.sproc2 ' + @param + ''' ) )' exec ( @sqlCommand ) Now in the called sproc2 I again call a third procedure sproc3 on another linked server, which returns my resultset. SET @sqlCommand = 'EXEC ' + @targetServer +'.database.usr.sproc3 ' + @param exec ( @sqlCommand ) The whole thing doen't work, as I get an SQL error 7391 The operation could not be performed because OLE DB provider "%ls" for linked server "%ls" was unable to begin a distributed transaction. I already checked the hints at this microsoft article, but without success. But maybe, I can change the code in sproc1. Would there be some alternative to the temp table and the open query? Just calling stored procedures from server A to B to C and returning the resultset is working (I do this often in the application). But this special case with the temp table and openquery doesn't work! Or is it just not possible what I am trying to do? The microsft article states: Check the object you refer on the destination server. If it is a view or a stored procedure, or causes an execution of a trigger, check whether it implicitly references another server. If so, the third server is the source of the problem. Run the query directly on the third server. If you cannot run the query directly on the third server, the problem is not actually with the linked server query. Resolve the underlying problem first. Is this my case? PS: I can't avoid the architecture with the three servers.

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• How to handle update events on a ASP.NET GridView?

  - by Bogdan M

  Hello, This may sound silly, but I need to find out how to handle an Update event from a GridView. First of all, I have a DataSet, where there is a typed DataTable with a typed TableAdapter, based on a "select all query", with auto-generated Insert, Update, and Delete methods. Then, in my aspx page, I have an ObjectDataSource related to my typed TableAdapter on Select, Insert, Update and Delete methods. Finnally, I have a GridView bound to this ObjectDataSource, with default Edit, Update and Cancel links. How should I implement the edit functionality? Should I have something like this? protected void GridView_RowEditing(object sender, GridViewEditEventArgs e) { using(MyTableAdapter ta = new MyTableAdapter()) { ta.Update(...); TypedDataTable dt = ta.GetRecords(); this.GridView.DataSource = dt; this.GridView.DataBind(); } } In this scenario, I have the feeling that I update some changes to the DB, then I retrive and bind all the data, and not only the modified parts. Is there any way to update only the DataSet, and this to update on his turn the DataBase and the GridView? I do not want to retrive all the data after a CRUD operations is performed, I just want to retrive the changes made. Thanks. PS: I'm using .NET 3.5 and VS 2008 with SP1.

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• Trying to write up a C daemon, but don't know enough C to continue

  - by JamesM-SiteGen

  Okay, so I want this daemon to run in the background with little to no interaction. I plan to have it work with Apache, lighttpd, etc to send the session & request information to allow C to generate a website from an object DB, saving will have to be an option so, you can start the daemon with an existing DB but will not save to it unless you login to the admin area and enable, and restart the daemon. Summary of the daemon: Load a database from file. Have a function to restart the daemon. Allow Apache, lighttpd, etc to get necessary data about the request and session. A varible to allow the database to be saved to the file, otherwise it will only be stored in ram. If it is set to save back to the file, then only have neccessary data in ram. Use sql-light for the database file. Build a webpage from some template files. $(myVar) for getting variables. Get templates from a directory. ./templates/01-test/{index.html,template.css,template.js} Live version of the code and more information: http://typewith.me/YbGB1h1g1p Also I am working on a website CMS in php, but I am tring to switch to C as it is faster than php. ( php is quite fast, but the fact that making a few mySQL requests for every webpage is quite unefficent and I'm sure that it can be far better, so an object that we can recall data from in C would have to be faster ) P.S I am using Arch-Linux not MS-Windows, with the package group base-devel for the common developer tools such as make and makepgk. Edit: Oupps, forgot the question ;) Okay, so the question is, how can I turn this basic C daemon into a base to what I am attempting to do here?

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• How to convert source code to a xml based representation of the ast?

  - by autobiographer

  i wanna get a xml representation of the ast of java and c code. 3 months ago, i asked this question yet but the solutions weren't comfortable for me srcml seems to be a good solution for this problem but it does not support line numbers and columns but i need that feature. about elsa: cite: "There is ongoing effort to export the Elsa AST as an XML document; we expect to be able to advertise this in the next public release." dms... didn't understand that. especially for java, there is javaml which supports line numbers. but the sourceforge page doesn't list any files. question: there's software available which supports conversion of ast into xml which supports line numbers (and columns) [especially for java and c/c++]? is there an alternative to javaml and srcml? ps: i don't wanne have parser generators. i hope to find a tool which can be used on the console typing: ./my-xml-generator Test.java [or something like that]... or a java implementation would be great too.

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• Grails or Play! for an ex-RoR developer ?

  - by Kedare

  Hello, I plan to begin learning a Java web framework (I love the Java API), I already used Rails and Django. I want something close to Java, but without all the complexity of J2EE. I've found 2 framework that could be good for me : Grails : Grails looks great, it use Groovy that is better than Java for web application (I think..), but it's slower, that use pure-java components (Hibernate, Strut, Spring), it looks pretty simple to deploy (send .war and it's ok !), the GSP is great ! It's a bit harder to debug (need to restart the server at each modification, and the stacktrace is a mix of Java and Groovy stack that is not always understandable..) Play! : This framework also looks great, it's faster than Grails (It's use directly Java), but I don't really like how it use Java, it modify the source code to transform the properties call as setXXX/getXXX, I'm not kind of that... The framework also have caching function that Grails don't (alreary) has. I don't really like the Template Engine. It's also easer to debug (no need to restart the server, and the stacktrace is clear) What do you recommend for ? I am looking for something easy to learn (I used a lot ruby and java, but a little bit java (But I love the Java API)), that is full featured (That's no a problem with all the Java Library availables, but if it's bundle and integrated I prefer), that scale and that is not too slow (faster than ruby), and if possible I would want something with a decent community to easily find support and answer to my questions ;) PS: No JRuby on Rails Thank you !

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• Can someone please debug this Windows Azure Application?

  - by Vimvq1987

  Here's the myTODO project from codeplex: myTODO project I added any necessary libraries, added storage, changed obsolete types/methods, but everything went wrong when I debug it. An exception was thrown here (in TableStorage.cs): public IEnumerable<TElement> ExecuteWithRetries(RetryPolicy retry) { IEnumerable<TElement> ret = null; if (retry == null) { throw new ArgumentNullException("retry"); } retry(() => { try { ret = _query.Execute(); } catch (InvalidOperationException e) { if (TableStorageHelpers.CanBeRetried(e)) { throw new TableRetryWrapperException(e); } throw; } }); return ret; } I'm using Visual Studio 2008, SQL server 2008, Windows Azure SDK v1.1. Can anyone please debug this project for me, or suggest me someway to get it working. This request is urgent. Any helps are much appreciated. PS: If you can't download these file, please let me know, I'll upload to another hosts.

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• NoClassDefFoundError without any class name

  - by Safder

  Hello, I am trying to run a java task from ant. I am trying to run the "org.apache.tools.ant.launch.Launcher" class. I keep on getting the "NoClassDefFoundError" without any class name being specified. I am also getting a "ClassNotFoundException" along with that displaying a message "Could not find the main class: . Program will exit". Here's a snippet of the error [java] Exception in thread "main" java.lang.NoClassDefFoundError: [java] Caused by: java.lang.ClassNotFoundException: [java] at java.net.URLClassLoader$1.run(URLClassLoader.java:200) [java] at java.security.AccessController.doPrivileged(Native Method) [java] at java.net.URLClassLoader.findClass(URLClassLoader.java:188) [java] at java.lang.ClassLoader.loadClass(ClassLoader.java:307) [java] at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) [java] at java.lang.ClassLoader.loadClass(ClassLoader.java:252) [java] at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) [java] Could not find the main class: . Program will exit. [java] Java Result: 1 Now I am trying to run an ant class from an ant jar and i specifiy the classpath where this class file resides using the "classpathref" attribute, however I still get this message. I checked the ant jar to check the Manifest and the "main" class is specified properly (it's "org.apache.tools.ant.launch.Launcher") . I have exhausted all my resources. Please help ! ! ! ps: My environment is Eclipse on Ubuntu 9.04

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• ISO/IEC Website and Charging for C and C++ Standards

  - by Michael Aaron Safyan

  The ISO C Standard (ISO/IEC 9899) and the ISO C++ Standard (ISO/IEC 14882) are not published online; instead, one must purchase the PDF for each of those standards. I am wondering what the rationale is behind this... is it not detrimental to both the C and C++ programming languages that the authoritative specification for these languages is not made freely available and searchable online? Doesn't this encourage the use of possibly inaccurate, non-authoritative sources for information regarding these standards? While I understand that much time and effort has gone into developing the C and C++ standards, I am still somewhat puzzled by the choice to charge for the specification. The OpenGroup Base Specification, for example, is available for free online; they make money buy charging for certification. Does anyone know why the ISO standards committees don't make their revenue in certifying standards compliance, instead of charging for these documents? Also, does anyone know if the ISO standards committee's atrociously looking website is intentionally made to look that way? It's as if they don't want people visiting and buying the spec. One last thing... the C and C++ standards are generally described as "open standards"... while I realize that this means that anyone is permitted to implement the standard, should that definition of "open" be revised? Charging for the standard rather than making it openly available seems contrary to the spirit of openness. P.S. I do have a copy of the ISO/IEC 9899:1999 and ISO/IEC 14882:2003, so please no remarks about being cheap or anything... although if you are tempted to say such things, you might want to consider the high school, undergraduate, and graduate students who might not have all that much extra cash. Also, you might want to consider the fact that the ISO website is really sketchy and they don't even tell you the cost until you proceed to the checkout... doesn't really encourage one to go and get a copy, now does it?

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• Signable, streamable, "readable" archive format?

  - by alexvoda

  Is there any archive format that offers the following: be digitally sign-able with a digital certificate from a trusted source like Verisign - for preventing changes to the file (I am not referring to read only, but in case the file was changed it should no longer be signed telling the user this is not the original file) be stream-able - be able to be opened even if not all of the content has been transfered (also not strictly linearly) be "readable" - be able to read the data without extracting to a temporary folder (AFAIK if you open a file in a zip archive it is extracted first, and this stays true even for zip based formats like OOXML. This is not what I want) be portable - support on at least Windows, Linux and Mac OS X is a must, or at least future support be free of patents - Be open source - also preferably a license that allows commercial use(as far as i know GPL a share-alike licence so it doesn't allow comercial use, BSD on the other hand alows it) Note: Though it may come in handy eventually I can not think right now of a scenario that would require both point 1 and point 2 simultaneously. Or lets leave it a be able to check the signature only when the whole file was downloaded. I am not interested in: being able to be compressed being supported on legacy systems Does any existing archive format fit this description (tar evolutions like DAR and pax come to mind) ? If there is, are there programing libraries available for the above mentioned OSs? If not, would it be hard to create such a thing? EDIT: clarrified piont 5 EDIT 2: added a note to clarify point 1 and 2 P.S.: This is my first question on StackOverflow

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• Server side form validation and POST data

  - by tomcritchlow

  Hi, I have a user input form here: http://www.7bks.com/create (Google login required) When you first create a list you are asked to create a public username. Unfortuantely currently there is no constraint to make this unique. I'm working on the code to enforce unique usernames at the moment and would like to know the best way to do it. Tech details: appengine, python, webapp framework What I'm planning is something like this: first the /create form posts the data to /inputlist/ (this is the same as currently happens) /inputlist/ queries the datastore for the given username. If it already exists then redirect back to /create display the /create page with all the info previously but with an additional error message of "this username is already taken" My question is: Is this the best way of handling server side validation? What's the best way of storing the list details while I verify and modify the username? As I see it I have 3 options to store the list details but I'm not sure which is "best": Store the list details in the session cookie (I am using GAEsessions for cookies) Define a separate POST class for /create and post the list data back from /inputlist/ to the /create page (currently /create only has a GET class) Store the list in the datastore, even though the username is non-unique. Thank you very much for your help :) I'm pretty new to python and coding in general so if I've missed something obvious my apologies. Tom PS - I'm sure I can eventually figure it out but I can't find any documentation on POSTing data using the webapp appengine framework which I'd need in order to do solution 2 above :s maybe you could point me in the right direction for that too? Thanks! PPS - It's a little out of date now but you can see roughly how the /create and /inputlist/ code works at the moment here: 7bks.com Gist

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• Yahoo Query Language Problem

  - by Damiano

  Hello everybody! Today, I've started with Yahoo Query Language. I would use it to retrive stocks details, so I'm talking about Yahoo Finance. I think there is a bug on this language. This is my query: select * from yahoo.finance.quoteslist where symbol='@^GSPC' I ALWAYS get 51 results! it's impossible, take a look at: http://it.finance.yahoo.com/q/cp?s=^GSPC There are 500 results! I also tried some paging parameters. select * from yahoo.finance.quoteslist(50,30) where symbol='@^GSPC' (to get from 50 to 80) select * from yahoo.finance.quoteslist(100) where symbol='@^GSPC' (to get the first 100 results) select * from yahoo.finance.quoteslist where symbol='@^GSPC' limit 30 offset 50 but ALWAYS the last stock is: <quote symbol="BBY"> <Symbol>BBY</Symbol> <LastTradePriceOnly>41.03</LastTradePriceOnly> <LastTradeDate>5/7/2010</LastTradeDate> <LastTradeTime>4:00pm</LastTradeTime> <Change>-0.48</Change> <Open>41.35</Open> <DaysHigh>42.35</DaysHigh> <DaysLow>39.60</DaysLow> <Volume>14129531</Volume> </quote> Why do I have this kind of problem? Thank you so much for your support! (P.S. I've tested it on Yahoo YQL console)

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• DataGrid calculate difference between values in two databound cells

  - by justMe

  Hello! In my small application I have a DataGrid (see screenshot) that's bound to a list of Measurement objects. A Measurement is just a data container with two properties: Date and CounterGas (float). Each Measurement object represents my gas consumption at a specific date. The list of measurements is bound to the DataGrid as follows: <DataGrid ItemsSource="{Binding Path=Measurements}" AutoGenerateColumns="False"> <DataGrid.Columns> <DataGridTextColumn Header="Date" Binding="{Binding Path=Date, StringFormat={}{0:dd.MM.yyyy}}" /> <DataGridTextColumn Header="Counter Gas" Binding="{Binding Path=ValueGas, StringFormat={}{0:F3}}" /> </DataGrid.Columns> </DataGrid> Well, and now my question :) I'd like to have another column right next to the column "Counter Gas" which shows the difference between the actual counter value and the last counter value. E.g. this additional column should calculate the difference between the value of of Feb. 13th and Feb. 6th = 199.789 - 187.115 = 15.674 What is the best way to achieve this? I'd like to avoid any calculation in the Measurement class which should just hold the data. I'd rather more like the DataGrid to handle the calculation. So is there a way to add another column that just calculates the difference between to values? Maybe using some kind of converter and extreme binding? ;D P.S.: Maybe someone with a better reputation could embed the screenshot. Thanks :)

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• problem with evolutionary algorithms degrading into simulated annealing: mutation too small?

  - by Schnalle

  i have a problem understanding evolutionary algorithms. i tried using this technique several times, but i always ran into the same problem: degeneration into simulated annealing. lets say my initial population, with fitness in brackets, is: A (7), B (9), C (14), D (19) after mating and mutation i have following children: AB (8.3), AC (12.2), AD (14.1), BC(11), BD (14.7), CD (17) after elimination of the weakest, we get A, AB, B, AC next turn, AB will mate again with a result around 8, pushing AC out. next turn, AB again, pushing B out (assuming mutation changes fitness mostly in the 1 range). now, after only a few turns the pool is populated with the originally fittest candidates (A, B) and mutations of those two (AB). this happens regardless of the size of the initial pool, it just takes a bit longer. say, with an initial population of 50 it takes 50 turns, then all others are eliminated, turning the whole setup in a more complicated simulated annealing. in the beginning i also mated canditates with themselves, worsening the problem. so, what do i miss? are my mutation rates simply too small and will it go away if i increase them? here's the project i'm using it for: http://stefan.schallerl.com/simuan-grid-grad/ yeah, the code is buggy and the interface sucks, but i'm too lazy to fix it right now - and be careful, it may lock up your browser. better use chrome, even thought firefox is not slower than chrome for once (probably the tracing for the image comparison pays off, yay!). if anyone is interested, the code can be found here. here i just dropped the ev-alg idea and went for simulated annealing. ps: i'm not even sure about simulated annealing - it is like evolutionary algorithms, just with a population size of one, right?

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• How do the size standard libraries compare for different languages

  - by Roman A. Taycher

  Someone was recently raving about how great jQuery was and how it made javascript into a pleasure and also how the whole source code was so small(and one file). I looked it up on www.ohloh.net/ and it said it was about 30,000 lines of javascript, when I tired curl piped to wc it said about 5000 lines(strange discrepancy that, maybe test suites, ect?). I thought well it isn't that strange since javascript from what I've heard has a lot of fun dynamic tricks, so you can probably get away with a small library. But then I thought what about other high level languages, the ones with large standard libraries and wondered how big the standard are for python/ruby/haskell/pharo(smalltalk)/*ml/ect. (libraries not vm stuff to the degree its possible to separate it) Anybody know? Any details (comment/blank/code lines , test code lines, lines in language vs lines in ffi/byte-code) are appreciated! edit: ps. since it started this me asking about jQuery as a bonus if you could please list the size of mega frameworks, a megaframewok provides so much that people using an x megaframework in language y might sometimes refer to programming in xy or even x rather then in y (ie. : qt, jQuery, etc.).

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• LinqToSql Select to a class then do more queries

  - by fyjham

  I have a LINQ query running with multiple joins and I want to pass it around as an IQueryable<T> and apply additional filters in other methods. The problem is that I can't work out how to pass around a var data type and keep it strongly typed, and if I try to put it in my own class (EG: .Select((a,b) => new MyClass(a,b))) I get errors when I try to add later Where clauses because my class has no translations into SQL. Is there any way I can do one of the following: Make my class map to SQL? Make the var data-type implement an interface (So I can pass it round as though it's that)? Something I haven't though of that'll solve my issue? Example: public void Main() { using (DBDataContext context = new DBDataContext()) { var result = context.TableAs.Join( context.TableBs, a => a.BID, b => b.ID, (a,b) => new {A = a, B = b} ); result = addNeedValue(result, 4); } } private ???? addNeedValue(???? result, int value) { return result.Where(r => r.A.Value == value); } PS: I know in my example I can flatten out the function easily, but in the real thing it'd be an absolute mess if I tried.

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• Why the composite component fails to parent controls?

  - by lyborko

  Hi, I created my own Component : TPage , which Contains Subcomponent TPaper (TPanel). The problem is, that when I put controls such as TMemo or TButton on the TPaper (which fills up nearly whole area), the controls do not load at all. see example below TPaper = class(TPanel) protected constructor Create(AOwner: TComponent);override; destructor Destroy;override; public procedure Paint; override; end; TPage = class(TCustomControl) private FPaper:TPaper; protected procedure CreateParams(var Params:TCreateParams); override; public constructor Create(AOwner: TComponent);override; destructor Destroy;override; published property Paper: TPaper read FPaper write FPaper; end; constructor TPage.Create(AOwner: TComponent); begin inherited Create(AOwner); PaperOrientation:=poPortrait; PaperSize:=psA4; PaperBrush:=TBrush.Create; PaperBrush.Color:=clWhite; PDFDocument:=Nil; FPaper:=TPaper.Create(Self); FPaper.Parent:=Self; FPaper.SetSubComponent(True); end; ... Memo1 is parented in TPaper (TPanel) at design-time, but after pressing "Run" it does not exist. procedure TForm1.btn1Click(Sender: TObject); begin if not Assigned(Memo1) then ShowMessage('I do not exist'); //Memo1 is nil end; Have you any idea what's wrong? Thanks a lot P.S Delphi 7 When I put TMemo inside TPaper and save the unit (Unit1), after inspection of associated dfm file, there is no trace of TMemo component. (Thats why it can not load to app.)

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• Implementing eval and load functions inside a scripting engine with Flex and Bison.

  - by Simone Margaritelli

  Hy guys, i'm developing a scripting engine with flex and bison and now i'm implementing the eval and load functions for this language. Just to give you an example, the syntax is like : import std.*; load( "some_script.hy" ); eval( "foo = 123;" ); println( foo ); So, in my lexer i've implemented the function : void hyb_parse_string( const char *str ){ extern int yyparse(void); YY_BUFFER_STATE prev, next; /* * Save current buffer. */ prev = YY_CURRENT_BUFFER; /* * yy_scan_string will call yy_switch_to_buffer. */ next = yy_scan_string( str ); /* * Do actual parsing (yyparse calls yylex). */ yyparse(); /* * Restore previous buffer. */ yy_switch_to_buffer(prev); } But it does not seem to work. Well, it does but when the string (loaded from a file or directly evaluated) is finished, i get a sigsegv : Program received signal SIGSEGV, Segmentation fault. 0xb7f2b801 in yylex () at src/lexer.cpp:1658 1658 if ( YY_CURRENT_BUFFER_LVALUE->yy_buffer_status == YY_BUFFER_NEW ) As you may notice, the sigsegv is generated by the flex/bison code, not mine ... any hints, or at least any example on how to implement those kind of functions? PS: I've succesfully implemented the include directive, but i need eval and load to work not at parsing time but execution time (kind of PHP's include/require directives).

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• Docs for auto-generated methods in Ruby on Rails

  - by macek

  Rails has all sorts of auto-generated methods that I've often times struggled to find documentation for. For example, in routes.rb, if I have: map.resources :projects do |p| p.resources :tasks end This will get a plethora of auto-generate path and url helpers. Where can I find documentation for how to work with these paths? I generally understand how to work with them, but more explicit docs might help me understand some of the magic that happens behind the scenes. # compare project_path(@project) project_task_path(@project, @task) # to project_path(:id => @project.id) project_task_path(:project_id => @project.id, :id => @task.id) Also, when I change an attribute on a model, @post.foo_changed? will be true. Where can I find documentation for this and all other magical methods that are created like this? If the magic is there, I'd love to take advantage of it. And finally: Is there a complete resource for config.___ statements for environment.rb? I was able to find docs for Configuration#gem but what attributes can I set within the stubs like config.active_record.___, config.action_mailer.___, config.action_controller.___, etc. Again, I'm looking for a complete resource here, not just a settings for the examples I provided. Even if you can only answer one of these questions, please chime in. These things seem to have been hiding from me and it's my goal to get them some more exposure, so I'll be upvoting all links to docs that point me to what I'm looking for. Thanks! ps, If they're not called auto-generated methods, I apologize. Someone can teach me a lesson here, too :) Edit I'm not looking for tutorials here, folks. I have a fair amount of experience with rails; I'm just looking for complete docs. E.g., I understand how routing works, I just want docs where I can read about all of the usage options.

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