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  • Subsetting a data frame in a function using another data frame as parameter

    - by lecodesportif
    I would like to submit a data frame to a function and use it to subset another data frame. This is the basic data frame: foo <- data.frame(var1= c('1', '1', '1', '2', '2', '3'), var2=c('A', 'A', 'B', 'B', 'C', 'C')) I use the following function to find out the frequencies of var2 for specified values of var1. foobar <- function(x, y, z){ a <- subset(x, (x$var1 == y)) b <- subset(a, (a$var2 == z)) n=nrow(b) return(n) } Examples: foobar(foo, 1, "A") # returns 2 foobar(foo, 1, "B") # returns 1 foobar(foo, 3, "C") # returns 1 This works. But now I want to submit a data frame of values to foobar. Instead of the above examples, I would like to submit df to foobar and get the same results as above (2, 1, 1) df <- data.frame(var1=c('1','1','3'), var2=c("A", "B", "C")) When I change foobar to accept two arguments like foobar(foo, df) and use y[, c(var1)] and y[, c(var2)] instead of the two parameters x and y it still doesn't work. Which way is there to do this?

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  • Coding guidelines + Best Practises?

    - by Chathuranga Chandrasekara
    I couldn't find any question that directly applies to my query so I am posting this as a new question. If there is any existing discussion that may help me, please point it out and close the question. Question: I am going to do a presentation on C# coding guidelines but it is not supposed to limit to coding standards. So I have a rough idea but I think I need to address good programing practices. So the contents will be something like this. Basic coding standards - Casing, Formatting etc. Good practices - Usage of Hashset over other data structures, String vs String Builder, String's immutability and using them effectively etc Really I would like to add more good practices (Especially to improve the performance.) So like to hear some more good practices to be used with C#. Any suggestions??? (No need of large descriptions :) Just the idea is sufficient.)

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  • Reading a file from a jar, or anywhere on the classpath?

    - by Stefan Kendall
    I'm trying to build an application that builds a resource file into a jar, but I'd like to have the project runnable within eclipse. I have a basic maven 2 structure for my project, and I'm unsure how to read in the file such that it's found and used when run from the JAR or from within eclipse. Thought? Structure: src/main/java src/main/resources/file.txt Current reading method: getClass().getResourceAsStream("/file.txt") Is there reading method that will pick up src/main/resources/*, as well as the root level of the JAR (where resources are deployed)?

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  • Is that a RESTFUL MVC Web Service?

    - by vsj
    I am aware of Web Services and WCF but I have generic question with services.I have a ASP.NET MVC Application which does some basic functionality. I just have a controller in which I am passing it the records and serializing the information to XML using XML Serializer. Then I return this information to the browser and it displays me the XML i got from the Controller Action. So I get the XML representation of my Class(Database Object) in XML and I am to give the URL of this application to the client and access and pull the information. Is this a Service then? I mean in the end all the Clients need is the Xml representation through services also right? I am not that experienced and probably being very silly but please help me out...if I provide xml this way to the client is that a Service ? Or is there something I need to undersatand here?.

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  • Memory cleanup on returned array from static method (objective-c)

    - by Michael Bordelon
    In objective-c, I have a utility class with a bunch of static methods that I call for various tasks. As an example, I have one method that returns an NSArray that I allocate in the static method. If I set the NSArray to autorelease, then some time later, the NSArray in my calling method (that is assigned to the returned pointer) losses it's reference because the original form the static method is cleaned up. I can't release the NSArray object in the static method because it needs to be around for the return and assignment. What is the right way to return an object (like the NSArray) from a static class, and have it hang around for the calling class, but then get cleaned up later when it is no longer needed? Do I have to create the object first in the caller and pass in a pointer to the object and then return that same object form the static method? I know this is a basic O-O problem, I just never had this issue in Java and I do not do much C/C++. Thanks for your help.

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  • How can I implement Unix grep in Perl?

    - by Ankit Rathod
    How can I implement grep of Unix in Perl? I tried to use Perl's built-in grep. Here is the code which is not working: $pattern = @ARGV[0]; $file= @ARGV[1]; open($fp,$file); @arr = <$fp>; @lines = grep $pattern, @arr; close($fp); print @lines; And by the way, i am trying only basic grep functionality not full featured and secondly i don't want to do string parsing myself. I want to use inbuilt grep or some function of Perl. Thanks in advance :)

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  • Creating Facebook Apps .. going mad

    - by ArneRie
    Hi, iam trying to create my first Application running inside an Facebook Canvas. Iam using Zend Framework (PHP) for this project. But iam not able to understand all the different ways facebook is offering. There is an PHP SDK wich works so far. There is an Javascript SDK and something called FBJS? Does someone knows a good point to start? The Documentation is not actual most times. I have managed it to login, and show my picture and name inside the app, the basic stuff is working.

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  • How to find all Classes implemeting IDisposable?

    - by apoorv020
    I am working on a large project, and one of my tasks is to remove possible memory leaks. In my code, I have noticed several IDisposable items not being disposed of, and have fixed that. However, that leads me to a more basic question, how do I find all classes used in my project that implement IDisposable? (Not custom created classes by normal Library classes). I have already found one less-than-obvious class that implements IDisposable ( DataTable implements MarshalByValueComponent, which inherits IDisposable). Right now, I am manually checking any suspected classes by using MSDN, but isn't there some way through which I can automate this process?

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  • bash : recursive listing of all files problem

    - by Michael Mao
    Run a recursive listing of all the files in /var/log and redirect standard output to a file called lsout.txt in your home directory. Complete this question WITHOUT leaving your home directory. An: ls -R /var/log/ /home/bqiu/lsout.txt I reckon the above bash command is not correct. This is what I've got so far: $ ls -1R .: cal.sh cokemachine.sh dir sort test.sh ./dir: afile.txt file subdir ./dir/subdir: $ ls -R | sed s/^.*://g cal.sh cokemachine.sh dir sort test.sh afile.txt file subdir But this still leaves all directory/sub-directory names (dir and subdir), plus a couple of empty newlines How could I get the correct result without using Perl or awk? Preferably using only basic bash commands(this is just because Perl and awk is out of assessment scope)

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  • Getting started with modern software architecture and design using a book

    - by bitbonk
    I am a rather oldschool developer with some basic knowledge of software design principles and a good background on classic (gof) design patterns. While I continue my life as such I see lots of strange buzzwords emerge: Aspectoriented Design, Componentoriented Design, Domain Driven Design, Domain Specific Languages, Serviceoriented (SOA) Design, Test Driven Design, Extreme Programming, Agile Development, Continuous Integration, Dependency Injection, Software Factories ... Is there good book around that I can take with me on a roadtrip while it is taking me on a trip through all (most) of the above, delivering an 10,000 foot view on modern software archiceture and desing principles and approaches.

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  • Issue Passing NSMutableDictionary to Method

    - by roswell
    Hello all, I'm trying some basic iPhone programming -- all has been going well but recently I've hit a bit of a roadblock. I've got a chunk of code that's passing an NSMutableDictionary (amongst other things) to a method in another class: [self.shuttle makeAPICallAndReturnResultsUsingMode:@"login" module:@"login" query:credentials]; The NSMutableArray credentials is previously defined a bit above as such: NSMutableDictionary *credentials = [[NSMutableDictionary alloc] init]; [credentials setObject:username forKey:@"username"]; [credentials setObject:password forKey:@"password"]; The method that receives it looks like such: -(id)makeAPICallAndReturnResultsUsingMode:(NSString *)mode module:(NSString *)module query:(NSMutableDictionary *)query From debugging I have determined that the code works fine up until this point within the above method: [query setObject:self.sessionID forKey:@"session_id"]; At this point, the application terminates -- the Console informs me of this exception: * Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '* -[NSCFDictionary setObject:forKey:]: method sent to an uninitialized mutable dictionary object' This leads me to believe that I must initialize NSMutableDictionary in some way in my new method before I can access it, but I have no idea how. Any advice?

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  • Xpath and parameters

    - by Daniel
    I am relatively new to XSL and I think this is a basic question. So I better get my apologies in early! Basically, I would like to use a value-of function. This will be in a template and I would like to pass part of the xpath as a parameter. <xsl:variable name="TEST_VAR">"h:elementA/elementB"</xsl:variable> ... and then use the variable (or passed in param) as all (or part) of the xpath: <xsl:element name="transformedElement"><xsl:value-of select=$TEST_VAR/></xsl:element> I would really like to have the xpath to be a mixture of string literals and the vlue of TEST_VAR. Thanks in advance

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  • SmartGWT Widgets not displaying properly

    - by Holograham
    I have a basic GWT Maven project going. I added SmartGWT and started playing around with some widgets and nothing displays correctly. The ListGrid seems to somewhat render but things are off and even data isnt showing up (though the rows respond to indicate there is data within the row). Sorting arrows dont appear but are clickable, and filters are wildy off. Whats causing this. I deleted everything in the .css file. GWT newbie here.

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  • WPF data grid - Column Header not aligned with data rows

    - by Pawan
    Hi, I am using Datagrid in WPF. This is a very simple and basic implementation. I not using any styles. I created a simple datagrid : <dg:DataGrid x:Name="dg" > </dg:DataGrid> and populated it with data as: dg.ItemsSource = " H E L L O W O R L D!".Split(); Grid gets properly populated but the columnheader of the grid is drawn with some offset. Due to this my data and header are mis aligned. I tried searching for this over net but I haven't found anything. This seems to be a straightforward implementation which is working for everyone except me :(. Can anyone please tell me what might be going wrong? I have tried using different data sets and appyling some style to test this. Thanks in advance.

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  • Batch file to wait for other program to load/initialize, then execute command?

    - by Jason N
    I need some assistance writing what should be a fairly basic .BAT file. I load my main program, but that program takes ~20secs to load and be initialized. I have another command-line API I can execute to interact with this above program, but obviously until the above program is loaded and initialized there's no point in trying. If the program isn't running the command-line API returns a string stating exactly this - otherwise it just works and exits. Easy. So I want to wait until the above is loaded/initialized before firing my API command(s) at it. I could place a sleep/wait in there, but I want something more solid. The ~20sec wait is not necessarily consistent. Any way to execute the command-line API over and over until the response is satisfactory, then exit? J

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  • Open source project home page

    - by Oskar Kjellin
    I've created a software that I want to be able to market. I'd like to be able to post it on forums etc and for that I need a home page. Is there any open source C# project home pages that you can use? The functionality I'm looking for is like adding new versions (perhaps a version control from the software), downloading and user guides. So what I want is pretty basic: I want to be able to upload and let the users download. I've written this on my own as well but I guess that if there are open source projects that have done this they're probably better. This can't be such a rare problem so please lead me to some resources so that I can create my page and publish my software! :)

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  • Fetching custom Authorization header from incoming PHP request

    - by jpatokal
    So I'm trying to parse an incoming request in PHP which has the following header set: Authorization: Custom Username Simple question: how on earth do I get my hands on it? If it was Authorization: Basic, I could get the username from $_SERVER["PHP_AUTH_USER"]. If it was X-Custom-Authorization: Username, I could get the username from $_SERVER["HTTP_X_CUSTOM_AUTHORIZATION"]. But neither of these are set by a custom Authorization, var_dump($_SERVER) reveals no mention of the header (in particular, AUTH_TYPE is missing), and PHP5 functions like get_headers() only work on responses to outgoing requests. I'm running PHP 5 on Apache with an out-of-the box Ubuntu install.

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  • python socket.recv/sendall call blocking

    - by fsm
    Hi everyone. This post is incorrectly tagged 'send' since I cannot create new tags. I have a very basic question about this simple echo server. Here are some code snippets. client while True: data = raw_input("Enter data: ") mySock.sendall(data) echoedData = mySock.recv(1024) if not echoedData: break print echoedData server while True: print "Waiting for connection" (clientSock, address) = serverSock.accept() print "Entering read loop" while True: print "Waiting for data" data = clientSock.recv(1024) if not data: break clientSock.send(data) clientSock.close() Now this works alright, except when the client sends an empty string (by hitting the return key in response to "enter data: "), in which case I see some deadlock-ish behavior. Now, what exactly happens when the user presses return on the client side? I can only imagine that the sendall call blocks waiting for some data to be added to the send buffer, causing the recv call to block in turn. What's going on here? Thanks for reading!

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  • How safe am I signing into Google Spreadsheets with yeroon.net/ggplot2

    - by Farrel
    I am impressed by what I have seen of yeroon.net/ggplot2 which is a web interface for Hadley Wickham's R package ggplot2. I want to try it out on my own data. The part that has me very excited is that one can use data stored in one's own Google spreadsheet as the data. One just signs into their Google Account so that yeroon.net/ggplot2 can access the spreadsheet list. I have been hesitant to do it. If I sign in whilst on yeroon.net am I handing over my username and password to a third party? It would not be wise of me to divulge my google password to third parties since Google is fast becoming my repository of everything. How do I know if Jeroon's application is using ClientLogin or OAuth? My understanding is very basic and may be wrong but nevertheless here it is. OAuth would be better since it does not actually pass the password onto the third party application.

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  • Is it feasible to write a Firefox plugin to make use of ActiveX control on Windows?

    - by Gary B2312321321
    I use an ActiveX control called TAPIEx enabling TAPI phone system integration using MS Access 2000 (+Visual Basic). I want to turn this Access database into a web app with the clients running Firefox (all on internal network). Since Firefox doesnt support ActiveX is it feasible for me to write a Firefox plugin that in turn utilizes the ActiveX control? With regard to how plugins work - Would I be able to call 'functions' of the plugin from page script (eg dial call specifying phone number, check if calls in process)? Would adding these functions to the Firefox right click menu 'globally' inside Firefox be easier? Hope you guys can help. Note I'm not a fulltime programmer; I just need to know how steep the learning curve will be or even if my idea is possible! Ive now found a project to allow using activex controls in firefox that seems to be quite up to date at: http://code.google.com/p/ff-activex-host/

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  • Handling inverted pixels in bitmapData and bitmap class in as3

    - by intoTHEwild
    I am using bitmapData and bitmap classes to render a mouse cursor on the display screen. The bitmapData consists of an area whose colors should be inverted according to the background color. This is a very basic thing which could be observed with text cursor(the vertical line with two small horizontals on top and bottom), when moved over the text area. I want to be able to do the same with the pixels in my bitmapData, is there a way to find out the background color effectively and invert the color values? In this process i will be redrawing the whole pixels, is there any other efficient way to do that ?

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  • improving conversions to binary and back in C#

    - by Saad Imran.
    I'm trying to write a general purpose socket server for a game I'm working on. I know I could very well use already built servers like SmartFox and Photon, but I wan't to go through the pain of creating one myself for learning purposes. I've come up with a BSON inspired protocol to convert the the basic data types, their arrays, and a special GSObject to binary and arrange them in a way so that it can be put back together into object form on the client end. At the core, the conversion methods utilize the .Net BitConverter class to convert the basic data types to binary. Anyways, the problem is performance, if I loop 50,000 times and convert my GSObject to binary each time it takes about 5500ms (the resulting byte[] is just 192 bytes per conversion). I think think this would be way too slow for an MMO that sends 5-10 position updates per second with a 1000 concurrent users. Yes, I know it's unlikely that a game will have a 1000 users on at the same time, but like I said earlier this is supposed to be a learning process for me, I want to go out of my way and build something that scales well and can handle at least a few thousand users. So yea, if anyone's aware of other conversion techniques or sees where I'm loosing performance I would appreciate the help. GSBitConverter.cs This is the main conversion class, it adds extension methods to main datatypes to convert to the binary format. It uses the BitConverter class to convert the base types. I've shown only the code to convert integer and integer arrays, but the rest of the method are pretty much replicas of those two, they just overload the type. public static class GSBitConverter { public static byte[] ToGSBinary(this short value) { return BitConverter.GetBytes(value); } public static byte[] ToGSBinary(this IEnumerable<short> value) { List<byte> bytes = new List<byte>(); short length = (short)value.Count(); bytes.AddRange(length.ToGSBinary()); for (int i = 0; i < length; i++) bytes.AddRange(value.ElementAt(i).ToGSBinary()); return bytes.ToArray(); } public static byte[] ToGSBinary(this bool value); public static byte[] ToGSBinary(this IEnumerable<bool> value); public static byte[] ToGSBinary(this IEnumerable<byte> value); public static byte[] ToGSBinary(this int value); public static byte[] ToGSBinary(this IEnumerable<int> value); public static byte[] ToGSBinary(this long value); public static byte[] ToGSBinary(this IEnumerable<long> value); public static byte[] ToGSBinary(this float value); public static byte[] ToGSBinary(this IEnumerable<float> value); public static byte[] ToGSBinary(this double value); public static byte[] ToGSBinary(this IEnumerable<double> value); public static byte[] ToGSBinary(this string value); public static byte[] ToGSBinary(this IEnumerable<string> value); public static string GetHexDump(this IEnumerable<byte> value); } Program.cs Here's the the object that I'm converting to binary in a loop. class Program { static void Main(string[] args) { GSObject obj = new GSObject(); obj.AttachShort("smallInt", 15); obj.AttachInt("medInt", 120700); obj.AttachLong("bigInt", 10900800700); obj.AttachDouble("doubleVal", Math.PI); obj.AttachStringArray("muppetNames", new string[] { "Kermit", "Fozzy", "Piggy", "Animal", "Gonzo" }); GSObject apple = new GSObject(); apple.AttachString("name", "Apple"); apple.AttachString("color", "red"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)1.5); GSObject lemon = new GSObject(); apple.AttachString("name", "Lemon"); apple.AttachString("color", "yellow"); apple.AttachBool("inStock", false); apple.AttachFloat("price", (float)0.8); GSObject apricoat = new GSObject(); apple.AttachString("name", "Apricoat"); apple.AttachString("color", "orange"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)1.9); GSObject kiwi = new GSObject(); apple.AttachString("name", "Kiwi"); apple.AttachString("color", "green"); apple.AttachBool("inStock", true); apple.AttachFloat("price", (float)2.3); GSArray fruits = new GSArray(); fruits.AddGSObject(apple); fruits.AddGSObject(lemon); fruits.AddGSObject(apricoat); fruits.AddGSObject(kiwi); obj.AttachGSArray("fruits", fruits); Stopwatch w1 = Stopwatch.StartNew(); for (int i = 0; i < 50000; i++) { byte[] b = obj.ToGSBinary(); } w1.Stop(); Console.WriteLine(BitConverter.IsLittleEndian ? "Little Endian" : "Big Endian"); Console.WriteLine(w1.ElapsedMilliseconds + "ms"); } Here's the code for some of my other classes that are used in the code above. Most of it is repetitive. GSObject GSArray GSWrappedObject

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  • Firefox Upload Form Issue

    - by cast01
    Ive created an uplaod script in php that takes a file, resizes it, and creates a cropped square thumbnail. The script itself seems to work fine. However, when i tried to upload an image through firefox, on clicking the submit button the browser shows the loading animation, but it never calls the script, it just stays on the current page. If dont upload an image, then the script can be found and is run. I tried in safari, and i dont get the same problem, i can upload an image from the form, it will process it and take me the correct page. Ive tired just calling a basic script from the form, it just prints out the $_POST and $_FILES, and i get the same result, if an image is present, it wont get to the script, if no image is present, it runs fine. Im just wondering if anyone has any idea whats going on?

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  • Text encoding problem between NSImage, NSData, and NSXMLDocument

    - by andyvn22
    I'm attempting to take an NSImage and convert it to a string which I can write in an XML document. My current attempt looks something like this: [xmlDocument setCharacterEncoding: @"US-ASCII"]; NSData* data = [image TIFFRepresentation]; NSString* string = [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding]; //Put string inside of NSXMLElement, write out NSXMLDocument. Reading back in looks something like this: NSXMLDocument* newXMLDocument = [[NSXMLDocument alloc] initWithData:data options:0 error:outError]; //Here's where it fails. I get: //Error Domain=NSXMLParserErrorDomain Code=9 UserInfo=0x100195310 "Line 7: Char 0x0 out of allowed range" I assume I'm missing something basic. What's up with this encoding issue?

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  • The speed of .NET in numerical computing

    - by Yin Zhu
    In my experience, .net is 2 to 3 times slower than native code. (I implemented L-BFGS for multivariate optimization). I have traced the ads on stackoverflow to http://www.centerspace.net/products/ the speed is really amazing, the speed is close to native code. How can they do that? They said that: Q. Is NMath "pure" .NET? A. The answer depends somewhat on your definition of "pure .NET". NMath is written in C#, plus a small Managed C++ layer. For better performance of basic linear algebra operations, however, NMath does rely on the native Intel Math Kernel Library (included with NMath). But there are no COM components, no DLLs--just .NET assemblies. Also, all memory allocated in the Managed C++ layer and used by native code is allocated from the managed heap. Can someone explain more to me? Thanks!

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