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  • onclick event in dropdown

    - by raam
    <html> <head> </style> <script type="text/javascript"> function ram(){ document.write("Hello World!") alert("ok"); } </script> </head> <body> <select id="country"> <option value="India" id="101" onfocus="ram()">India</option> <option value="Autralia" id="102" onClick="ram();">Autralia</option> <option value="England" id="103" onfocus="ram();">England</option> <option value="Ameriaca" id="104" onfocus="ram();">Ameriaca</option> <option value="Pakistan" selected="selected" id="105" onfocus="ram();" >Pakistan</option> </select> </body> </html> In this above code the event will not fire for dropdown. I try by using focus and click event. I can I do this and I want 1 more thing if I select dropdown value as India, I want to create a dropdown with state (elements are TN, DL, etc) updation.

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  • php (rar) i want to rar a folder using rar on Ubuntu (linux) by php (on dedi server) noob

    - by Steve
    hey guyz i want rar (not tar) my folder on my server by using php RAR RAR 3.93 Copyright (c) 1993-2010 Alexander Roshal 15 Mar 2010 Registered to my real name OS Ubuntu Release (Karmic) kernel linux 2.6.32.2-xxxx-grs-ipv4-32 Gnome 2.28.1 latest php an lighthttpd i have tried these things http://php.net/manual/en/function.escapeshellarg.php // may be wrong code http://php.net/manual/en/function.exec.php http://php.net/manual/en/function.shell-exec.php my command (working in ssh and nautilus script) rar a -m0 /where/file/will/saved/file_name.rar /location/ti/data/dir/datafolder php code $log=Shell_exec("rar a -m0 /where/file/will/saved/file_name.rar /location/ti/data/dir/datafolder"); echo $log; one method is left which i don't know how to use and its working on server that is by somefile_to_execute_command.sh i have to execute .sh file from php need to send some variables (command) and i tried this method can rar file with a script named RapidLeech but its rar from only its own files dir only :( but i want to do in different directories. Rapid Leech rar class http://paste2.org/p/791668 i m able run shell command with php (cp(copy),mv(move),ls(directory list),rm(remove aka delete)) but got failed to run rar i gives no output i also tried to given path rar and i used alot commands with php Shell_exec function and working like they work with ssh and i have tried almost 80 % method given on net and failed from last 3days i m over now plz help me i need php script file working plz reply if u have any info n code and experience about rar and this kinda :( problem i m 99% noob just used code mean search Google collect script make my own working thing (for personal use only) n now i m failed to rar folder and file :(( now plz provide me code plz don't talk in technical language because i m just reading my first php book (for dummies :D) mean noob and 0.1 plz help me as much u can thankx

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  • is there a Universal Model for languages?

    - by Smandoli
    Many programming languages share generic and even fairly universal features. For example, if you compared Java, VB6, .NET, PHP, Python, then you would find common functions such as control structures, numeric and string manipulation, etc. What has been done to define these features at a meta-language (or language-agnostic) level? UML offers a descriptive reference of software in every aspect, but the real-world focus seems to be data processes. Is UML relevant? I'm not asking "Why we don't have a single language that replaces the current plethora." We need many different tools (at least in this eon). I'm not asking that all languages fit a template -- assembly vs. compiled languages are different enough to make that unfeasible (and some folks call HTML a language, though I wouldn't). Any attempt would start with a properly narrow scope. In line with this, I wouldn't expect the model to cover even a small selection with full validity. I would expect however that such a model could be used to transpose from one language to another (with limited goals -- think jist translation).

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  • Handle order dependence in loops

    - by Matt
    Hey all, I'm making a templating system where I instantiate each tag using a foreach loop. The issue is that some of the tags rely on each other so, I'm wondering how to get around that ordering from the looping. Here's an example: Class A { public $width; __construct() { $this->width = $B->width; // Undefined! Or atleast not set yet.. } } Class B { public $width; __construct() { $this->width = "500px"; } __tostring() { return "Hello World!"; } } Template.php $tags = array("A", "B"); foreach ($tags as $tag) { $TagObj[$tag] = new $tag(); } echo $TagObj['A']->width; // Nadamundo! EDIT: Ok just to clarify.. My main problem is that Class A relies on Class B, but class A is instantiated before class B, so therefore width has not yet been defined in class B. I am looking for a good way to make sure all the classes are loaded for everyone allowing the interdependencies to exist. For the future, please don't consider any syntax errors.. I just made up this example on the spot. Also assume that I have access to class B from class A after class B gets instantiated. I know this has applications elsewhere and I'm sure this has been solved before, if someone could enlighten me or point me in the right direction that'd be great! Thanks! Matt Mueler

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  • How can I access mainframe data with .Net applications and SQL Queries?

    - by orandov
    We have a large amount of data stored on an IBM mainframe using VSAM files. A lot of this data is dropped on the network every night in the form of text files to be processed and dumped into FoxPro and SQL Server databases. There are also many text files produced nightly by custom applications that get uploaded to the mainframe to keep everything in sync. Keeping the everything in sync is very tricky, to say the least. We are not getting rid of the mainframe any time soon and we would like to replace all the nightly batch processing with real time access to the mainframe data. We would like to be able to: Read data directly from the mainframe and produce reports based on it. Possibly using SQL queries. Read and Write data from custom .Net applications. We are not looking for a new platform to interface with the mainframe like Information Builders offers. We don't want to build application modules or reports with new "Business Intelligence" tools. We already know how to generate reports and write custom applications using SQL,.Net, Visual Studio, etc. All we are looking for is some sort of adapter to connect to our mainframe data. Any ideas are appreciated.

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  • Rhino Mocks Partial Mock

    - by dotnet crazy kid
    I am trying to test the logic from some existing classes. It is not possible to re-factor the classes at present as they are very complex and in production. What I want to do is create a mock object and test a method that internally calls another method that is very hard to mock. So I want to just set a behaviour for the secondary method call. But when I setup the behaviour for the method, the code of the method is invoked and fails. Am I missing something or is this just not possible to test without re-factoring the class? I have tried all the different mock types (Strick,Stub,Dynamic,Partial ect.) but they all end up calling the method when I try to set up the behaviour. using System; using MbUnit.Framework; using Rhino.Mocks; namespace MMBusinessObjects.Tests { [TestFixture] public class PartialMockExampleFixture { [Test] public void Simple_Partial_Mock_Test() { const string param = "anything"; //setup mocks MockRepository mocks = new MockRepository(); var mockTestClass = mocks.StrictMock<TestClass>(); //record beahviour *** actualy call into the real method stub *** Expect.Call(mockTestClass.MethodToMock(param)).Return(true); //never get to here mocks.ReplayAll(); //this is what i want to test Assert.IsTrue(mockTestClass.MethodIWantToTest(param)); } public class TestClass { public bool MethodToMock(string param) { //some logic that is very hard to mock throw new NotImplementedException(); } public bool MethodIWantToTest(string param) { //this method calls the if( MethodToMock(param) ) { //some logic i want to test } return true; } } } }

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  • How to use log4j for a axis2 webservice

    - by KItis
    I have created a simple axis2 webservice to understand logging functionality in a webservice. in this sample webservice, when a client calls this webservice, first it reads the log4j.property file. then i can see the logs being printed on console. but i have included file appender too into the property file. but i can not file the log file any where in my sample webapplication. i am using tomcat to run the webservice. following is webservice interface method called by client. package test; import java.io.IOException; import java.io.InputStream; import java.util.Properties; import org.apache.log4j.BasicConfigurator; import org.apache.log4j.Logger; import org.apache.log4j.PropertyConfigurator; public class WSInterface { static final Logger logger = Logger.getLogger(WSInterface.class); public String log4jTest(String input){ InputStream inputStream = this.getClass().getClassLoader() .getResourceAsStream(input); Properties properties = new Properties(); System.out.println("InputStream is: " + inputStream); //load the inputStream using the Properties try { properties.load(inputStream); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } PropertyConfigurator.configure(properties); logger.debug("Hello World!"); Class myclass = WSInterface.class; String url = myclass.getResource("WSInterface.class").toString(); String output = ""; return url; } }

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  • Is there a significant mechanical difference between these faux simulations of default parameters?

    - by ccomet
    C#4.0 introduced a very fancy and useful thing by allowing default parameters in methods. But C#3.0 doesn't. So if I want to simulate "default parameters", I have to create two of that method, one with those arguments and one without those arguments. There are two ways I could do this. Version A - Call the other method public string CutBetween(string str, string left, string right, bool inclusive) { return str.CutAfter(left, inclusive).CutBefore(right, inclusive); } public string CutBetween(string str, string left, string right) { return CutBetween(str, left, right, false); } Version B - Copy the method body public string CutBetween(string str, string left, string right, bool inclusive) { return str.CutAfter(left, inclusive).CutBefore(right, inclusive); } public string CutBetween(string str, string left, string right) { return str.CutAfter(left, false).CutBefore(right, false); } Is there any real difference between these? This isn't a question about optimization or resource usage or anything (though part of it is my general goal of remaining consistent), I don't even think there is any significant effect in picking one method or the other, but I find it wiser to ask about these things than perchance faultily assume.

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  • VSTO Word ContentControls, Y U No have Name property?

    - by System.Cats.Lol
    When you add a VSTO (not Word native) content control, you specify the name: controls.AddContentControl(wordRange, "foo", wdType); Where controls is the VSTO (extended) Document.Controls collection. You can later look up the control by name: ContentControl myContentControl = controls["foo"]; So why in the world is there no Name property for ContentControl? (or ContentControlBase, or any of the other derivatives). I'm implementing a wrapper class for the Document.Controls property that lets you add or iterate the content controls. When iterating the underlying Document.Controls, there's no way to look up the name of each control. (We need it to return an instance of our ContentControl wrapper). So currently I'm doing this in our ContentControls wrapper class: public IEnumerator<IContentControl> GetEnumerator() { System.Collections.IEnumerator en = this.wordControls.GetEnumerator(); while (en.MoveNext()) { // VSTO Document.Controls includes all managed controls, not just // VSTO ContentControls; return only those. if (en.Current is Microsoft.Office.Tools.Word.ContentControl) { // The control's name isn't stored with the control, only when it was added, // so use a placeholder name for the wrapper. yield return new ContentControl("Unknown", (Microsoft.Office.Tools.Word.ContentControl)en.Current); } } } I'd prefer to not have to resort to keeping a map of names-to-wrapper-objects in our ContentControls object. Can anyone tell me how to get the control's name (the name parameter that was passed to Controls.Add()?

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  • How can i add image in email body

    - by Kutbi
    final Intent i = new Intent(android.content.Intent.ACTION_SEND); i.putExtra(android.content.Intent.EXTRA_EMAIL, new String[]{ txt.getText().toString()}); i.putExtra(Intent.EXTRA_SUBJECT, "Merry Christmas"); i.setType("text/html"); Spanned html =Html.fromHtml("<html><body>h<b>ell</b>o<img src='http://www.pp.rhul.ac.uk/twiki/pub/TWiki/GnuPlotPlugin/RosenbrockFunctionSample.png'>world</body></html>", new ImageGetter() { InputStream s; public Drawable getDrawable(String url) { try { s = (InputStream) (new URL(url)).getContent(); } catch (MalformedURLException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } Drawable d = Drawable.createFromStream(s, null); LogUtil.debug(this, "Got image: " + d.getClass() + ", " + d.getIntrinsicWidth() + "x" + d.getIntrinsicHeight()); d.setBounds(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight()); return d; }},null); i.putExtra(Intent.EXTRA_TEXT, html); startActivity(Intent.createChooser(i, "Send email"));*

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  • Netlogo: error when putting variable in table, only constants allowe??

    - by Chantal
    Hello, Currently I am working on a Netlogo program where I need to use nodes and links for vehicle routing problem. (links are called streets in the program) Here I have some practical problems of how to input variable linkspeed in a table with another node. Constants like 200 etc are fine. Online I found some examples where variables are used, but I do not know why I keep getting the following error: Expected a constant. (or why netlogo expects a constant) Here is the relevant piece of code: extensions [table] streets-own [linkspeed linktoll] nodes-own [netw] ;; In another piece of code linkspeed is assigned successfully to the links to cheapcalc ;; start conditions set costs very high 300000 ;; state 3 unsearched state 2 searching state 1 searched (for later purposes) ask nodes [ set i 0 set j count nodes set netw table:make while [i < j][ table:put netw (i) [3000000 3] set i (i + 1)]] set i 0 let k 0 ask node 35 ;; here i use node 35 as an example. ;; node 35 is connected to node 34, 36, 20 and 50 [table:put netw (35) [0 1] ;; node need to search costs to travel to itself ;; putting constants is ok. while [i < j] [ask my-links [ask both-ends [if (who != 35) [set color blue ;; set temp ([linkspeed] of street 35 who) ;; here my real goal is to put this in stat of i. but i is easier than linkspeed. table:put netw (who) [ i 2 ] ] ] ] set i (i + 1)] ] ;; next node for later, no it is just repetition of the same. end I hope somebody knows what is going on... Kind regards, Chantal

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  • Using Partitions for a large MySQL table

    - by user293594
    An update on my attempts to implement a 505,000,000-row table on MySQL on my MacBook Pro: Following the advice given, I have partitioned my table, tr: i UNSIGNED INT NOT NULL, j UNSIGNED INT NOT NULL, A FLOAT(12,8) NOT NULL, nu BIGINT NOT NULL, KEY (nu), key (A) with a range on nu. nu ought to be a real number, but because I only have 6-d.p. accuracy and the maximum value of nu is 30000. I multiplied it by 10^8 made it a BIGINT - I gather one can't use FLOAT or DOUBLE values to PARTITION a MySQL table. Anyway, I have 15 partitions (p0: nu<25,000,000,000, p1: nu<50,000,000,000, etc.). I was thinking that this should speed up a typical to SELECT: SELECT * FROM tr WHERE nu>95000000000 AND nu<100000000000 AND A.>1. to something of the order of the same query on a table consisting of only the data in the relevant partition (<30 secs). But it's taking 30mins+ to return rows for queries within a partition and double that if the query is for rows spanning two (contiguous) partitions. I realise I could just have 15 different tables, and query them separately, but is there a way to do this 'automatically' with partitions? Has anyone got any suggestions?

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  • Groovy / Scala / Java under the hood

    - by Jack
    I used Java for like 6-7 years, then some months ago I discovered Groovy and started to save a lot of typing.. then I wondered how certain things worked under the hood (because groovy performance is really poor) and understood that to give you dynamic typing every Groovy object is a MetaClass object that handles all the things that the JVM couldn't handle by itself. Of course this introduces a layer in the middle between what you write and what you execute that slows down everything. Then somedays ago I started getting some infos about Scala. How these two languages compare in their byte code translations? How much things they add to the normal structure that it would be obtained by plain Java code? I mean, Scala is static typed so wrapper of Java classes should be lighter, since many things are checked during compile time but I'm not sure about the real differences of what's going inside. (I'm not talking about the functional aspect of Scala compared to the other ones, that's a different thing) Can someone enlighten me? From WizardOfOdds it seems like that the only way to get less typing and same performance would be to write an intermediate translator that translates something in Java code (letting javac compile it) without alterating how things are executed, just adding synctatic sugar withour caring about other fallbacks of the language itself.

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  • shielding #include within namespace { } block?

    - by Jeff
    Edit: I know that method 1 is essentially invalid and will probably use method 2, but I'm looking for the best hack or a better solution to mitigate rampant, mutable namespace proliferation. I have multiple class or method definitions in one namespace that have different dependencies, and would like to use the fewest namespace blocks or explicit scopings possible but while grouping #include directives with the definitions that require them as best as possible. I've never seen any indication that any preprocessor could be told to exclude namespace {} scoping from #include contents, but I'm here to ask if something similar to this is possible: (see bottom for explanation of why I want something dead simple) // NOTE: apple.h, etc., contents are *NOT* intended to be in namespace Foo! // would prefer something most this: namespace Foo { #include "apple.h" B *A::blah(B const *x) { /* ... */ } #include "banana.h" int B::whatever(C const &var) { /* ... */ } #include "blueberry.h" void B::something() { /* ... */ } } // namespace Foo ... // over this: #include "apple.h" #include "banana.h" #include "blueberry.h" namespace Foo { B *A::blah(B const *x) { /* ... */ } int B::whatever(C const &var) { /* ... */ } void B::something() { /* ... */ } } // namespace Foo ... // or over this: #include "apple.h" namespace Foo { B *A::blah(B const *x) { /* ... */ } } // namespace Foo #include "banana.h" namespace Foo { int B::whatever(C const &var) { /* ... */ } } // namespace Foo #include "blueberry.h" namespace Foo { void B::something() { /* ... */ } } // namespace Foo My real problem is that I have projects where a module may need to be branched but have coexisting components from the branches in the same program. I have classes like FooA, etc., that I've called Foo::A in the hopes being able to branch less painfully as Foo::v1_2::A, where some program may need both a Foo::A and a Foo::v1_2::A. I'd like "Foo" or "Foo::v1_2" to show up only really once per file, as a single namespace block, if possible. Moreover, I tend to prefer to locate blocks of #include directives immediately above the first definition in the file that requires them. What's my best choice, or alternatively, what should I be doing instead of hijacking the namespaces?

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  • C#/LINQ: How to define generically a keySelector for a templated class before calling OrderBy

    - by PierrOz
    Hi Folks, I have the following class defined in C# class myClass<T,U> { public T PropertyOne { get; set; } public U PropertyTwo { get; set; } } I need to write a function that reorder a list of myClass objects and takes two other parameters which define how I do this reorder: does my reordering depend on PropertyOne or PropertyTwo and is it ascending or descending. Let's say this two parameters are boolean. With my current knowledge in LINQ, I would write: public IList<myClass<T,U>> ReOrder(IList<myClass<T,U>> myList, bool usePropertyOne, bool ascending) { if (usePropertyOne) { if (ascending) { return myList.OrderBy(o => o.PropertyOne).ToList(); } else { return myList.OrderByDescending(o => o.PropertyOne).ToList(); } } else { if (ascending) { return myList.OrderBy(o => o.PropertyTwo).ToList(); } else { return myList.OrderByDescending(o => o.PropertyTwo).ToList(); } } } What could be a more efficient/elegant way to do that ? How can I declare the Func,TResult keySelector object to reuse when I call either OrderBy or OrderByDescending? I'm interesting in the answer since in my real life, I can have more than two properties.

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  • Common lisp, CFFI, and instantiating c structs

    - by andrew
    Hi, I've been on google for about, oh, 3 hours looking for a solution to this "problem." I'm trying to figure out how to instantiate a C structure in lisp using CFFI. I have a struct in c: struct cpVect{cpFloat x,y;} Simple right? I have auto-generated CFFI bindings (swig, I think) to this struct: (cffi:defcstruct #.(chipmunk-lispify "cpVect" 'classname) (#.(chipmunk-lispify "x" 'slotname) :double) (#.(chipmunk-lispify "y" 'slotname) :double)) This generates a struct "VECT" with slots :X and :Y, which foreign-slot-names confirms (please note that I neither generated the bindings or programmed the C library (chipmunk physics), but the actual functions are being called from lisp just fine). I've searched far and wide, and maybe I've seen it 100 times and glossed over it, but I cannot figure out how to create a instance of cpVect in lisp to use in other functions. Note the function: cpShape *cpPolyShapeNew(cpBody *body, int numVerts, cpVect *verts, cpVect offset) Takes not only a cpVect, but also a pointer to a set of cpVects, which brings me to my second question: how do I create a pointer to a set of structs? I've been to http://common-lisp.net/project/cffi/manual/html_node/defcstruct.html and tried the code, but get "Error: Unbound variable: PTR" (I'm in Clozure CL), not to mention that looks to only return a pointer, not an instance. I'm new to lisp, been going pretty strong so far, but this is the first real problem I've hit that I can't figure out. Thanks!

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  • Using SHFileOperation: What errors are occuring

    - by Sascha
    Hello I am using the function SHFileOperation() to send a file to the recycling bin. And I am getting 2 errors that I do not know what they mean because with this function the error codes are not GetLastError() values. Now when the function SHFileOperation() fails the return values are 0x57 (decimal 87) & 0x2 (decimal 2). Can you help me discover the definitions of these errors (expecially when you consider with this function, the errors are not part of the GetLastError() codes). Some important information: • I am using Windows 7 (& I know that MSDN says to use IFileOperation instead of SHFileOperation but I want to make my app backwards compatable which is why I am using SHFileOperation). If the error is occuring because I am using SHFileOperation on Windows 7 what solution could I use to make this work on all versions of windows from 2000 & up? • I have debugged extensively & as far as I know my SHFILEOPSTRUCT is correct (correct flags used, .pFrom is a double-null ended string). One thing I know for sure is that my path to the file is correct (leads to a real file & it correctly formatted). • About 2/5 times the SHFileOperation() works, meaning it sends the file to the recycle bin & does not returns an error BOOL result; SHFILEOPSTRUCT fileStruct; fileStruct.hwnd = hwnd; fileStruct.wFunc = FO_DELETE; fileStruct.pFrom = dest.c_str(); fileStruct.fFlags = FOF_FILESONLY; // FOF_ALLOWUNDO fileStruct.fAnyOperationsAborted = result; // Call operation(delete file) int success = SHFileOperation( &fileStruct ); // if delete was successful if ( success != 0 ) { printf( "%s \t %X %d \n", dest.c_str(), success, success ); cout << result << endl; MessageBox( hwnd, "Failed to delete file", "Error", MB_OK|MB_ICONERROR ); return; }

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  • How to format the Facebook news feed description of grouped app posts?

    - by JcFx
    I have an app which posts a message like this to a user's Facebook timeline: This is working fine, but if I post a few times, my posts get grouped on my news feed, and I get this: What settings should I use to control the way this news report appears? Instead of 'All about periods' and the page link in the box at the top, I'd like 'Body iQ Quiz' and the app description. Where would I set these values? And is it possible to make the grouped report say 'Jay cee Effex shared a link via Body iQ Quiz', the way the original post does? I'm posting from the Facebook AS3 API, and my post code looks like this: var auth:FacebookAuthResponse = Facebook.getAuthResponse(); var token:String = auth.accessToken; var user:String = auth.uid; var values:Object = { access_token: token, name: "Body iQ Quiz", picture: "http://a7.sphotos.ak.fbcdn.net/hphotos-ak-snc6/282950_427728213914009_630526316_n.jpg", link:"http://www.lil-lets.co.uk/en-GB/Wellbeing", description: "Women, how well do we know our bodies? Click here to find out what your Body iQ is.", message: result.FacebookBody + " " + result.FacebookTitle }; Facebook.api("/" + user + "/feed", handleSubmitFeed, values, URLRequestMethod.POST); ... but I'm not sure if this is something I can fix in code, or if the app configuration needs tweaking? NOTE: Some users report getting the latter format in their news feed even with a single post (I can't reproduce this), so perhaps grouping is a red herring, and the real question is how to format the news feed report of a timeline post?

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  • Perl+Image::Magick usage: how to assemble several areas in one image into a new image?

    - by Jin
    Hi Everybody, I'm new to ImageMagick and haven't figured out how to assemble several areas into a new image. E.g., I know the "geometry" of words "hello" and "world" respectively in an image, what I need to do is to retrieve the word images and put then into one line image while keep their relative positions. Question1: Suppose I use the perl API, how should I use Composite() or other correct methods to do this? my $geom = sprintf('%dx%x+%d+%d', $word->{width}, $word->{height}, $offsetx, $offsety); $x = $lineimg->Composite($wordimg, $geom); warn "$x" if "$x"; Suppose $lineimg's size is big enough to hold all word images and the geometry has been computed. This code gives out a complain by ImageMagick: Exception 410: composite image required `Image::Magick' @ Magick.xs/XS_Image__Magick_Mogrify/7790 ... Question2: currently I only know how to crop a word image out of the original one and then Clone() method to restore the original image. Is there a way to copy instead of crop a specific area from a image? This way can save the time to copy back and forth the whole image several times. Does anybody know how to write this kind of processing? I appreciate all your help and suggestions! -Jin

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  • Is my method for avoiding dynamic_cast<> faster than dynamic_cast<> itself ?

    - by ereOn
    Hi, I was answering a question a few minutes ago and it raised to me another one: In one of my projects, I do some network message parsing. The messages are in the form of: [1 byte message type][2 bytes payload length][x bytes payload] The format and content of the payload are determined by the message type. I have a class hierarchy, based on a common class Message. To instanciate my messages, i have a static parsing method which gives back a Message* depending on the message type byte. Something like: Message* parse(const char* frame) { // This is sample code, in real life I obviously check that the buffer // is not NULL, and the size, and so on. switch(frame[0]) { case 0x01: return new FooMessage(); case 0x02: return new BarMessage(); } // Throw an exception here because the mesage type is unknown. } I sometimes need to access the methods of the subclasses. Since my network message handling must be fast, I decived to avoid dynamic_cast<> and I added a method to the base Message class that gives back the message type. Depending on this return value, I use a static_cast<> to the right child type instead. I did this mainly because I was told once that dynamic_cast<> was slow. However, I don't know exactly what it really does and how slow it is, thus, my method might be as just as slow (or slower) but far more complicated. What do you guys think of this design ? Is it common ? Is it really faster than using dynamic_cast<> ? Any detailed explanation of what happen under the hood when one use dynamic_cast<> is welcome !

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  • How does one create and use a pointer to an array of an unknown number of structures inside a class?

    - by user1658731
    Sorry for the confusing title... I've been playing around with C++, working on a project to parse a game's (Kerbal Space Program) save file so I can modify it and eventually send it over a network. I'm stuck with storing an unknown number of vessels and crew members, so I need to have an array of unknown size. Is this possible? I figured having a pointer to an array would be the way to go. I have: class SaveFileSystem { string version; string UT; int activeVessel; int numCrew; ??? Crews; // !! int numVessels; ??? Vessels; // !! } Where Crews and Vessels should be arrays of structures: struct Crew { string name; //Other stuff }; struct Vessel { string name; //Stuff }; I'm guessing I should have something like: this->Crews = new ???; this->Vessels = new ???; in my constructor to initialize the arrays, and attempt to access it with: this->Crews[0].name = "Ship Number One"; Does this make any sense??? I'd expect the "???"'s to involve a mess of asterisk's, like "*struct (*)Crews" but I have no real idea. I've got normal pointers down and such, but this is a tad over my head... I'd like to access the structures like in the last snippet, but if C++ doesn't like that I could do pointer arithmetic. I've looked into vectors, but I have an unhealthy obsession with efficiency, and it really pains me how you don't know what's going on behind it.

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  • How to publish internal data to the internet - as simple as possible

    - by mlarsen
    We have a .net 2-tier application where a desktop program is talking to a database. We support MS SQL Server 2000, 2005, 2008 and Oracle 9, 10 and 11. The application is sold, not as shrink-wrap, but pretty close. It is quite important for us that the installation and configuration is as easy as possible as installation instructions are usually supplied in written form to the customers internal IT-department. Our application is usually not seen as mission critical for the IT-department, so we need to keep their work down to a minimum. Now we are starting to get wishes for a web application build on top of the same data. The web application will be hosted by us and delivered as a SaaS application. Now the challenge is how to move data back and forth between the web application and the customers internal database. as I see it we have some requirements: We must be ready to handle the situation where the customers database is not accessible from the DMZ. I guess the easiest solution is that all communication is initiated from inside the customers lan. As little firewall configuration as possible. The best is if we can run without any special configuration as long as outgoing traffic from the customers lan are not blocked. If we need something changed in the firewall, we must be able to document that the change is secure. It doesn't have to be real time. Moving data in batches every ten minutes or so is OK. Data moves both ways, but not the same tables, so we don't have to support merges. It would be nice if we don't have to roll our own framework completely. Looking forward to hear your suggestions.

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  • Mercurial: applying changes one by one to resolve merging issues

    - by Webinator
    I recently tried to merge a series of changeset and encountered a huge number of merging issues. Hence I'd like to to try to apply each changeset, in order, one by one, in order to make the merging issues easier to manage. I'll give an example with 4 problematic changesets (514,515,516 and 517) [in my real case, I've got a bit more than that] o changeset: 517 | o changeset: 516 | o changeset: 515 | o changeset: 514 | | | @ changeset: 513 | | | o changeset: 512 | | | o | | | o | | | o |/ | | o changeset 508 Note that I've got clones of my repos before pulling the problematic changesets. When I pull the 4 changesets and try a merge, things are too complicated to resolve. So I wanted to pull only changeset 514, then merge. Then once I solve the merging issue, pull only changeset 515 and apply it, etc. (I know the numbering shall change, this is not my problem here). How am I supposed to do that, preferably without using any extension? (because I'd like to understand Mercurial and what I'm doing better). Is the way to go generate a patch between 508 and 514 and apply that patch? (if so, how would I generate that patch) Answers including concrete command-line example(s) most welcome :)

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  • Bilinear interpolation - DirectX vs. GDI+

    - by holtavolt
    I have a C# app for which I've written GDI+ code that uses Bitmap/TextureBrush rendering to present 2D images, which can have various image processing functions applied. This code is a new path in an application that mimics existing DX9 code, and they share a common library to perform all vector and matrix (e.g. ViewToWorld/WorldToView) operations. My test bed consists of DX9 output images that I compare against the output of the new GDI+ code. A simple test case that renders to a viewport that matches the Bitmap dimensions (i.e. no zoom or pan) does match pixel-perfect (no binary diff) - but as soon as the image is zoomed up (magnified), I get very minor differences in 5-10% of the pixels. The magnitude of the difference is 1 (occasionally 2)/256. I suspect this is due to interpolation differences. Question: For a DX9 ortho projection (and identity world space), with a camera perpendicular and centered on a textured quad, is it reasonable to expect DirectX.Direct3D.TextureFilter.Linear to generate identical output to a GDI+ TextureBrush filled rectangle/polygon when using the System.Drawing.Drawing2D.InterpolationMode.Bilinear setting? For this (magnification) case, the DX9 code is using this (MinFilter,MipFilter set similarly): Device.SetSamplerState(0, SamplerStageStates.MagFilter, (int)TextureFilter.Linear); and the GDI+ path is using: g.InterpolationMode = InterpolationMode.Bilinear; I thought that "Bilinear Interpolation" was a fairly specific filter definition, but then I noticed that there is another option in GDI+ for "HighQualityBilinear" (which I've tried, with no difference - which makes sense given the description of "added prefiltering for shrinking") Followup Question: Is it reasonable to expect pixel-perfect output matching between DirectX and GDI+ (assuming all external coordinates passed in are equal)? If not, why not? Finally, there are a number of other APIs I could be using (Direct2D, WPF, GDI, etc.) - and this question generally applies to comparing the output of "equivalent" bilinear interpolated output images across any two of these. Thanks!

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  • How can I SETF an element in a tree by an accessor?

    - by Willi Ballenthin
    We've been using Lisp in my AI course. The assignments I've received have involved searching and generating tree-like structures. For each assignment, I've ended up writing something like: (defun initial-state () (list 0 ; score nil ; children 0 ; value 0)) ; something else and building my functions around these "states", which are really just nested lists with some loosely defined structure. To make the structure more rigid, I've tried to write accessors, such as: (defun state-score ( state ) (nth 2 state)) This works for reading the value (which should be all I need to do in a nicely functional world. However, as time crunches, and I start to madly hack, sometimes I want a mutable structure). I don't seem to be able to SETF the returned ...thing (place? value? pointer?). I get an error with something like: (setf (state-score *state*) 10) Sometimes I seem to have a little more luck writing the accessor/mutator as a macro: (defmacro state-score ( state ) `(nth 2 ,state)) However I don't know why this should be a macro, so I certainly shouldn't write it as a macro (except that sometimes it works. Programming by coincidence is bad). What is an appropriate strategy to build up such structures? More importantly, where can I learn about whats going on here (what operations affect the memory in what way)?

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