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  • Fix DB duplicate entries (MySQL bug)

    - by Silence
    I'm using MySQL 4.1. Some tables have duplicates entries that go against the constraints. When I try to group rows, MySQL doesn't recognise the rows as being similar. Example: Table A has a column "Name" with the Unique proprety. The table contains one row with the name 'Hach?' and one row with the same name but a square at the end instead of the '?' (which I can't reproduce in this textfield) A "Group by" on these 2 rows return 2 separate rows This cause several problems including the fact that I can't export and reimport the database. On reimporting an error mentions that a Insert has failed because it violates a constraint. In theory I could try to import, wait for the first error, fix the import script and the original DB, and repeat. In pratice, that would take forever. Is there a way to list all the anomalies or force the database to recheck constraints (and list all the values/rows that go against them) ? I can supply the .MYD file if it can be helpful.

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  • Custom setter methods in Core-Data

    - by andrewebling
    I need to write a custom setter method for a field (we'll call it foo) in my subclass of NSManagedObject. foo is defined in the data model and Xcode has autogenerated @property and @dynamic fields in the .h and .m files respectively. If I write my setter like this: - (void)setFoo: (NSObject *)inFoo { [super setFoo: inFoo]; [self updateStuff]; } then I get a compiler warning on the call to super. Alternatively, if I do this: - (void)setFoo: (NSObject *)inFoo { [super setValue: inFoo forKey: inFoo]; [self updateStuff]; } then I end up in an infinite loop. So what's the correct approach to write a custom setter for a subclass of NSManagedObject?

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  • MinGW screw up with COLORREF and RGB

    - by kjoppy
    I am trying to build a 3rd party open source project using MinGW. One of the dependencies is wxWidgets. When I try to make the project from MSYS I get a compiler error from /MinGW/msys/1.0/local/include/wx-2.8/wx/msw/private.h In function 'COLORREF wxColourToRGB(const wxColour&)': error: cannot convert 'RGB' to 'COLORREF {aka long unsigned in}' in return This is somewhat odd given that, according to Microsoft the RGB macro returns a COLORREF. In fact, looking in H:\MinGW\include I find wingdi.h with the following code #define RGB(r,g,b) ((COLORREF)((BYTE)(r)|((BYTE)(g) << 8)|((BYTE)(b) << 16))) What sort of thing would cause this error? Is there some way I can check to see if COLORREF and RGB are being included from wingdi.h and not somewhere else? Is that even worth checking? Specifications GCC version 4.7.2 wxWidgets version 2.8.12 (I'm new to C++ and MinGW specifically but generally computer and programming literate)

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  • HOW TO understand the programmming of operation system..!!!

    - by piemesons
    Hello, I want to learn the operating system. How it works. I dont want to make my own operating system. I just want to learn how it works. As i can find out source code of any open source OS. But how to start. Like stating from the first elementary kernal(what ever it is). Some body suggested me try to implement linux from scratch.etc etc.Please guide me in a proper way. i want to know about the proper path to follow. I am ready to invest three four years just to understand the basics. I am having good fundamentals of c c++,php, Oops, compiler design

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  • Connect to a website via HTTP in C

    - by sfactor
    i have a C code that parses a file and generates another file for the processed data. i now need to send these files to a web server (website). i guess there way is to do a HTTP POST. but i have never done this in c (Linux gcc compiler in ubuntu). Does anyone know how to do this. i need to a starting point as i have no clue of doing this in C. i also need to be able to authenticate with the website.

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  • C++ is there a difference between assignment inside a pass by value and pass by reference function?

    - by Rémy DAVID
    Is there a difference between foo and bar: class A { Object __o; void foo(Object& o) { __o = o; } void bar(Object o) { __o = o; } } As I understand it, foo performs no copy operation on object o when it is called, and one copy operation for assignment. Bar performs one copy operation on object o when it is called and another one for assignment. So I can more or less say that foo uses 2 times less memory than bar (if o is big enough). Is that correct ? Is it possible that the compiler optimises the bar function to perform only one copy operation on o ? i.e. makes __o pointing on the local copy of argument o instead of creating a new copy?

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  • Reducing Dimension For SVM in Sensor Network

    - by iinception
    Hi Everyone, I am looking for some suggestions on a problem that I am currently facing. I have a set of sensor say S1-S100 which is triggered when some event E1-E20 is performed. Assume, normally E1 triggers S1-S20, E2 triggers S15-S30, E3 triggers S20-s50 etc and E1-E20 are completely independent events. Occasionally an event E might trigger any other unrelated sensor. I am using ensemble of 20 svm to analyze each event separately. My features are sensor frequency F1-F100, number of times each sensor is triggered and few other related features. I am looking for a technique that can reduce the dimensionality of the sensor feature(F1-F100)/ or some techniques that encompasses all of the sensor and reduces the dimension too(i was looking for some information theory concept for last few days) . I dont think averaging, maximization is a good idea as I risk loosing information(it did not give me good result). Can somebody please suggest what am I missing here? A paper or some starting idea... Thanks in advance.

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  • Programming texts and reference material for my Kindle DX, creating the ultimate reference device?

    - by mwilliams
    (Revisiting this topic with the release of the Kindle DX) Having owned both generation Kindle readers and now getting a Kindle DX; I'm very excited for true PDF handling on an e-ink device! An image of _Why's book on my Kindle (from my iPhone). This gives me a device capable of storing hundreds of thousands of pages that are full text search capable in the form factor of a magazine. What references (preferably PDF to preserve things such as code samples) would you recommend? Ultimately I would like reference material for every modern and applicable programming language (C, C++, Objective-C, Python, Ruby, Java, .NET (C#, Visual Basic, ASP.NET), Erlang, SQL references) as well as general programming texts and frameworks (algorithms, design patterns, theory, Rails, Django, Cocoa, ORMs, etc) and anything else that could be thought of. With so many developers here using such a wide array of languages, as a professional in your particular field, what books or references would you recommend to me for my Kindle? Creative Commons material a plus (translate that to free) as well as the material being in the PDF file format. File size is not an issue. If this turns out to be a success, I will update with a follow-up with a compiled list generated from all of the answers. Thanks for the assistance and contributing! UPDATE I have been using the Kindle DX a lot now for technical books. Check out this blog post I did for high resolution photos of different material: http://www.matthewdavidwilliams.com/2009/06/12/technical-document-pdfs-on-the-kindle-dx/

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  • Is it possible to come over the time out issue for a function call in C#?

    - by infant programmer
    In my program I call a method xslTransform.Load(strXmlQueryTransformPath, xslSettings, new XmlUrlResolver()); The problem I am facing is: sometimes this function doesn't execute well within the time. Sometimes compiler raises the time out issue after a long time of trial.. which inturn causes this part of application to shut. That is what I want to avoid. So if it exceeds certain time say 10 seconds I need to recall the method. Is it possible to add some code lines adjacent to this, which can meet the requirement?

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  • Can Haskell's monads be thought of as using and returning a hidden state parameter?

    - by AJM
    I don't understand the exact algebra and theory behind Haskell's monads. However, when I think about functional programming in general I get the impression that state would be modelled by taking an initial state and generating a copy of it to represent the next state. This is like when one list is appended to another; neither list gets modified, but a third list is created and returned. Is it therefore valid to think of monadic operations as implicitly taking an initial state object as a parameter and implicitly returning a final state object? These state objects would be hidden so that the programmer doesn't have to worry about them and to control how they gets accessed. So, the programmer would not try to copy the object representing the IO stream as it was ten minutes ago. In other words, if we have this code: main = do putStrLn "Enter your name:" name <- getLine putStrLn ( "Hello " ++ name ) ...is it OK to think of the IO monad and the "do" syntax as representing this style of code? putStrLn :: IOState -> String -> IOState getLine :: IOState -> (IOState, String) main :: IOState -> IOState -- main returns an IOState we can call "state3" main state0 = putStrLn state2 ("Hello " ++ name) where (state2, name) = getLine state1 state1 = putStrLn state0 "Enter your name:"

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  • floating constants in C

    - by Daziplqa
    Hi floks, I have a question concerning floating constants in C. In Java, the default type of floating point constants in double, so the following will causes a compilation error in java: float f = 100.0; // we either need to uses type case operator or put f at the end of the number constant. This is because the default floating-point constants are of type double and casting from double to float without type cast operator is an error, so we need either add a type case operator or put f at the end of the number. So, Why in C this doesn't produce an error, Is it because the default floating-point constants are of type float, or because the compiler do an implicit down-cast conversion (that doesn't requires type case operator in C)????

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  • On Memory Allocation and C++

    - by Arpan
    And I quote from MSDN http://msdn.microsoft.com/en-us/library/aa366533(VS.85).aspx: The malloc function has the disadvantage of being run-time dependent. The new operator has the disadvantage of being compiler dependent and language dependent. Now the questions folks: a) What do we mean that malloc is run-time dependent? What kind of dynamic memory allocation functions can be independent of run-time? This statement sounds real strange. b) new is language dependent? Of course it should be right? Are HeapAlloc, LocalAlloc etc language independent? c) From a pure performance perspective are the MSVC provided routines preferable? Arpan

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  • How we run a .NET 32-bit application in a 64-bit Windows server?

    - by Geo
    We are installing a third party application in one of our 64-bit Windows servers. This application apparently was build with the compiler option set to choose the platform at run time. When we run the application it gives us an error: System.BadImageFormatException: is not a valid Win32 application. I have seen in MSDN forums that in order to fix this error I have to build the application set to 32-bit, and that way it will run fine on a 64-bit server. I check on other StackOverflow links Other Posts. How to get around this situation? For everyone that wants to know more information: The application is running fine in a 32-bit test server. IIS version 6 using SQL Server Express 2005 On the Web Service Extension there are both Framework64\v2.0.50727\aspnet_isapi.dll and Framework\v2.0.50727\aspnet_isapi.dll

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  • .NET 4.0 Generic Invariant, Covariant, Contravariant

    - by Sameer Shariff
    Here's the scenario i am faced with: public abstract class Record { } public abstract class TableRecord : Record { } public abstract class LookupTableRecord : TableRecord { } public sealed class UserRecord : LookupTableRecord { } public interface IDataAccessLayer<TRecord> where TRecord : Record { } public interface ITableDataAccessLayer<TTableRecord> : IDataAccessLayer<TTableRecord> where TTableRecord : TableRecord { } public interface ILookupTableDataAccessLayer<TLookupTableRecord> : ITableDataAccessLayer<TLookupTableRecord> where TLookupTableRecord : LookupTableRecord { } public abstract class DataAccessLayer<TRecord> : IDataAccessLayer<TRecord> where TRecord : Record, new() { } public abstract class TableDataAccessLayer<TTableRecord> : DataAccessLayer<TTableRecord>, ITableDataAccessLayer<TTableRecord> where TTableRecord : TableRecord, new() { } public abstract class LookupTableDataAccessLayer<TLookupTableRecord> : TableDataAccessLayer<TLookupTableRecord>, ILookupTableDataAccessLayer<TLookupTableRecord> where TLookupTableRecord : LookupTableRecord, new() { } public sealed class UserDataAccessLayer : LookupTableDataAccessLayer<UserRecord> { } Now when i try to cast UserDataAccessLayer to it's generic base type ITableDataAccessLayer<TableRecord>, the compiler complains that it cannot implicitly convert the type.

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  • How to parse (infinite) nested object notation?

    - by kyogron
    I am currently breaking my head about transforming this object hash: "food": { "healthy": { "fruits": ['apples', 'bananas', 'oranges'], "vegetables": ['salad', 'onions'] }, "unhealthy": { "fastFood": ['burgers', 'chicken', 'pizza'] } } to something like this: food:healthy:fruits:apples food:healthy:fruits:bananas food:healthy:fruits:oranges food:healthy:vegetables:salad food:healthy:vegetables:onions food:unhealthy:fastFood:burgers food:unhealthy:fastFood:chicken food:unhealthy:fastFood:pizza In theory it actually is just looping through the object while keeping track of the path and the end result. Unfortunately I do not know how I could loop down till I have done all nested. var path; var pointer; function loop(obj) { for (var propertyName in obj) { path = propertyName; pointer = obj[propertyName]; if (pointer typeof === 'object') { loop(pointer); } else { break; } } }; function parse(object) { var collection = []; }; There are two issues which play each out: If I use recurse programming it looses the state of the properties which are already parsed. If I do not use it I cannot parse infinite. Is there some idea how to handle this? Regards

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  • How do you make your Java application memory efficient?

    - by Boune
    How do you optimize the heap size usage of an application that has a lot (millions) of long-lived objects? (big cache, loading lots of records from a db) Use the right data type Avoid java.lang.String to represent other data types Avoid duplicated objects Use enums if the values are known in advance Use object pools String.intern() (good idea?) Load/keep only the objects you need I am looking for general programming or Java specific answers. No funky compiler switch. Edit: Optimize the memory representation of a POJO that can appear millions of times in the heap. Use cases Load a huge csv file in memory (converted into POJOs) Use hibernate to retrieve million of records from a database Resume of answers: Use flyweight pattern Copy on write Instead of loading 10M objects with 3 properties, is it more efficient to have 3 arrays (or other data structure) of size 10M? (Could be a pain to manipulate data but if you are really short on memory...)

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  • Design pattern: polymorphisim for list of objects

    - by ziang
    Suppose I have a class A, and A1, A2 inherits from A. There are 2 functions: List<A1> getListA1(){...} List<A2> getListA2(){...} Now I want to do something similar to both A1 and A2 in another function public void process(List<A>){...} If I want to pass the instance of either ListA1 or ListA2, of course the types doesn't match because the compiler doesn't allow the coercion from List< A1 to List< A. I can't do something like this: List<A1> listA1 = getListA1(); List<A> newList = (List<A>)listA1; //this is not allowed. So what is the best approach to the process()? Is there any way to do it in a universal way rather than write the similar code to both List and List?

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  • How does SVN store commit time

    - by Salman
    I am working on a project that involves extracting details from a SVN server using SVNKit. My project is already complete and has been working we for a while now. During the testing, I noticed something rather very strange. the Commit Times my extract data seems is alway different from whats there in SVN Logs. I couldnt find any code in my project that could be inducing this difference but now I am looking as to how SVN server stores the Commit time in itself. As we have developer working from different part of the world thus resulting in different timezones, I was thinking that SVN might be storing time after converting them to GMT or timezone of the system on which SVN server is running. But that does not seem to be happening. Instead the times are stored as per the time when the commit was done and in that local timezone itself. I have been unable to find any substantial document on internet to support my theory so far. Can anybody in brief explain as how SVN store the Commit Time for each change? Documentaion links referring to this will be of great help.

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  • How should open source libraries be used on Windows?

    - by Jason Owen
    There are many open-source libraries that can be compiled with Visual Studio. I'm porting a program from Linux to Windows, but it depends on a number of libraries. I don't know what the best practices regarding libraries are on Windows. On Linux, these libraries are typically part of the distribution. To use sqlite on Debian, for example, you need only to install libsqlite3-dev and the include files and libraries (both static and dynamic) are automatically installed and available to your program. If you need a different version than your distribution supplies, you can compile it in your home directory, install it to ~/include and ~/lib, and set the appropriate environment variables so that your compiler includes those directories in its search path. What is the best way to use libraries that are distributed as source on Windows? If I link dynamically rather than statically, is there an easy way to copy required DLLs into the output directory to ease redistribution (assuming license requirements are met)?

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  • Excess elements in scalar initializer

    - by Wade Williams
    I'm pretty noobish when it comes to C++ STL stuff. After a compiler upgrade, I'm getting: error: Semantic Issue: Excess elements in scalar initializer on the call: Certificate *tempcert; cValType( tempPerson->name, tempcert ); with a typedef of: typedef std::map< string, certificate* >::value_type cValType; I'm not certain what this error is telling me or how to fix it. (Ok, I realize it's telling me excess elements, but it looks like it matches the map prototype to me, so I'm confused.) Suggestions?

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  • When will YOU adopt C++0x?

    - by HighCommander4
    I'm particularly looking for input from managers of ongoing C++ projects: Have you already adopted C++0x? If so, what has your experience been like? If you haven't adopted C++0x yet, are you planning to? If so, what is your timeline (in rough terms)? Are there any obstacles that are holding you back from adopting C++0x? Perhaps you are waiting for your favourite compiler or IDE to catch up? For managers of open source projects: are you afraid that adopting C++0x will mean less developers who are willing/able to contribute because they don't know the new features? Or, on the other hand, do you think most developers have been eagerly awaiting C++0x, and and will jump at the opportunity to use it? Do you think C++0x is stable enough to be adopted by a large project?

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  • Global variable not stable after platform changed.

    - by user350555
    Our embedded system is built on a hw/sw platform made by enea. After the platform updated recently, we found some operations on the global variable keep crashing the system. For example, we have a global map structure holding some data. We can insert/iterate the map once or twice, then the address of the elements in the map suddenly changed to some forbidden addresses like 0x0 or 0x1d, the system just crash. The only different before/after the platform update is : 1) sw part: It's a c++ software and We changed the compiler from diab cc to gcc. 2) hw part: we have a new board, but the cpu is still powerpc405s. I tried every possible way but still can't figure out the reason. Any thoughts?

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  • Using array of asp inside javascript is not working in the loop

    - by Poomjai
    I have a problem that when i bring the array of asp and use it in the javascript, When i use the counter (i++) and print for each index of array just like "<%=app[i] %" and it is not return the value back to me. Please help me i solve this problem for a day !!!-Thanks ^_^ edit <% String[] asp = {"a","b","c"}; %> <script language="javascript"> for(var i=0;i<"<%=asp %>".length;i++){ document.write("<%=asp[i] %>") } </script> the error is = Compiler Error Message: CS0103: The name 'i' does not exist in the current context

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  • Why size_t arguments in template declaration need to be const?

    - by ArunSaha
    I can have std::bitset< 10 > bitsetA; or const size_t LengthB = 20; std::bitset< LengthB > bitsetB; without any problem. But, if the length is not const size_t LengthC = 30; std::bitset< LengthC > bitsetC; // Line 30, say I face the following compilation error 'LengthC' cannot appear in a constant-expression template argument 1 is invalid What is the reason for that? What would be the problem, for compiler and for user code, if line 30 was to be accepted? Is it because LengthC might have some alias?

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  • SIFR, JAVASCRIPT & PHP - How to apply SIFR to dynamically loaded content.

    - by user311039
    Well here's the problem: I have a PHP index page which uses show/hide layers javascript. I am using the on menu.click function to show and hide content relevant to each menu. On.click all divs are hidden except the content for that menu item , which fades in. The content relating to each menu item are displayed within separate DIVS. The property is applied to all the text within all the divs. See: http://jobe-group.com/jobeco/uk/2010live/dynamic/content/index.php# The trouble is that SIFR only appears to be applied to the displayed on.load when the page is first loaded. When this is hidden and the other s shown through the "show" function they load in classic CSS fonts without the SIFR applied. Is this unavoidable with the SIFR setup. Or am I not calling the divs properly. I have set the SIFR to apply to the selector and indeed it works fine on the for the displayed on load. It doesn't work for the within other . In theory I would think its possible to load the SIFR on all divs on page.load even if those divs are presently visibility:hidden. What's the verdict on this? Hope someone can help. Cheers, John

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