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  • How do you avoid an invalid search space in a genetic algorithm?

    - by Dave
    I am developing a GA for a school project and I've noticed that upon evaluating my functions for fitness, an individual is equivalent to its inverse. For example, the set (1, 1, -1, 1) is equivalent to (-1, -1, 1, -1). To shrink my search space and reach a solution more efficiently, how can I avoid my crossovers from searching in this second half of the search space?

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  • multithreading with database

    - by Darsin
    I am looking out for a strategy to utilize multithreading (probably asynchronous delegates) to do a synchronous operation. I am new to multithreading so i will outline my scenario first. This synchronous operation right now is done for one set of data (portfolio) based on the the parameters provided. The (psudeo-code) implementation is given below: public DataSet DoTests(int fundId, DateTime portfolioDate) { // Get test results for the portfolio // Call the database adapter method, which in turn is a stored procedure, // which in turns runs a series of "rule" stored procs and fills a local temp table and returns it back. DataSet resultsDataSet = GetTestResults(fundId, portfolioDate); try { // Do some local processing on the results DoSomeProcessing(resultsDataSet); // Save the results in Test, TestResults and TestAllocations tables in a transaction. // Sets a global transaction which is provided to all the adapter methods called below // It is defined in the Base class StartTransaction("TestTransaction"); // Save Test and get a testId int testId = UpdateTest(resultsDataSet); // Adapter method, uses the same transaction // Update testId in the other tables in the dataset UpdateTestId(resultsDataSet, testId); // Update TestResults UpdateTestResults(resultsDataSet); // Adapter method, uses the same transaction // Update TestAllocations UpdateTestAllocations(resultsDataSet); // Adapter method, uses the same transaction // It is defined in the base class CommitTransaction("TestTransaction"); } catch { RollbackTransaction("TestTransaction"); } return resultsDataSet; } Now the requirement is to do it for multiple set of data. One way would be to call the above DoTests() method in a loop and get the data. I would prefer doing it in parallel. But there are certain catches: StartTransaction() method creates a connection (and transaction) every time it is called. All the underlying database tables, procedures are the same for each call of DoTests(). (obviously). Thus my question are: Will using multithreading anyway improve performance? What are the chances of deadlock especially when new TestId's are being created and the Tests, TestResults and TestAllocations are being saved? How can these deadlocked be handled? Is there any other more efficient way of doing the above operation apart from looping over the DoTests() method repeatedly?

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  • Store java.util.Calendar field into one column

    - by Rasika
    How to store java.util.Calendar field into one column with Datanucleus JDO. By default it is stored into two columns (millisecs, Timezone) with following JDO metadata. field name="startDate" serialized="true" embedded="true" persistence-modifier="persistent" What need to be changed in metadata to store it into single column (Timestamp)? Is it posible query (JDOQL) on calendar field when it is in two clumn?

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  • How to test my GAE site for performance

    - by Sergey Basharov
    I am building a GAE site that uses AJAX/JSON for almost all its tasks including building the UI elements, all interactions and client-server requests. What is a good way to test it for highloads so that I could have some statistics about how much resources 1000 average users per some period of time would take. I think I can create some Python functions for this purpose. What can you advise? Thanks.

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  • output with "Private`" Content in Mathematica Package

    - by madalina
    Hello everyone, I am trying to solve the following implementation problem in Mathematica 7.0 for some days now and I do not understand exactly what is happening so I hope someone can give me some hints. I have 3 functions that I implemented in Mathematica in a source file with extension *.nb. They are working okay to all the examples. Now I want to put these functions into 3 different packages. So I created three different packages with extension .*m in which I put all the desired Mathematica function. An example in the "stereographic.m" package which contain the code: BeginPackage["stereographic`"] stereographic::usage="The package stereographic...." formEqs::usage="The function formEqs[complexBivPolyEqn..." makePoly::usage="The function makePoly[algebraicEqn] ..." getFixPolys::usage="The function..." milnorFibration::usage="The function..." Begin["Private`"] Share[]; formEqs[complex_,{m_,n_}]:=Block[{complexnew,complexnew1, realeq, imageq, expreal, expimag, polyrealF, polyimagF,s,t,u,v,a,b,c,epsilon,x,y,z}, complexnew:=complex/.{m->s+I*t,n->u+I*v}; complexnew1:=complexnew/.{s->(2 a epsilon)/(1+a^2+b^2+c^2),t->(2 b epsilon)/(1+a^2+b^2+c^2),u->(2 c epsilon)/(1+a^2+b^2+c^2),v->(- epsilon+a^2 epsilon+b^2 epsilon+c^2 epsilon)/(1+a^2+b^2+c^2)}; realeq:=ComplexExpand[Re[complexnew1]]; imageq:=ComplexExpand[Im[complexnew1]]; expreal:=makePoly[realeq]; expimag:=makePoly[imageq]; polyrealF:=expreal/.{a->x,b->y,c->z}; polyimagF:=expimag/.{a->x,b->y,c->z}; {polyrealF,polyimagF} ] End[] EndPackage[] Now to test the function I load the package Needs["stereographic`"] everything is okay. But when I test the function for example with formEqs[x^2-y^2,{x,y}] I get the following ouput: {Private`epsilon^2 + 2 Private`x^2 Private`epsilon^2 + Private`x^4 Private`epsilon^2 - 6 Private`y^2 Private`epsilon^2 + 2 Private`x^2 Private`y^2 Private`epsilon^2 + Private`y^4 Private`epsilon^2 - 6 Private`z^2 Private`epsilon^2 + 2 Private`x^2 Private`z^2 Private`epsilon^2 + 2 Private`y^2 Private`z^2 Private`epsilon^2 + Private`z^4 Private`epsilon^2, 8 Private`x Private`y Private`epsilon^2 + 4 Private`z Private`epsilon^2 - 4 Private`x^2 Private`z Private`epsilon^2 - 4 Private`y^2 Private`z Private`epsilon^2 - 4 Private`z^3 Private`epsilon^2} Of course I do not understand why Private` appears in front of any local variable which I returned in the final result. I would want not to have this Private` in the computed output. Any idea or better explanations which could indicate me why this happens? Thank you very much for your help. Best wishes, madalina

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  • send blank SMS with SmsManager.sendTextMessage method in android

    - by Dany Wehbe
    I created an android app and one of its functions is to send SMS, when I try to send blank SMS it throws an exception. Here is the code: SmsManager sm=SmsManager.getDefault(); sm.sendTextMessage("9999", null, messageBody,sentPI, deliveredPI); messageBody maybe empty string and maybe it is a string, previous method throws IllegalArgumentException when messageBody is empty string! what can I do to send blank SMS?

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  • OpenCV performance in different languages

    - by h0b0
    I'm doing some prototyping with OpenCV for a hobby project involving processing of real time camera data. I wonder if it is worth the effort to reimplement this in C or C++ when I have it all figured out or if no significant performance boost can be expected. The program basically chains OpenCV functions, so the main part of the work should be done in native code anyway.

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  • need a project design tool

    - by santosh
    I am looking for simple and easy to use tools through which I can get project's visual picture of folder/file tree stucture , its classes, functions and objects, relations between classes and files.

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  • Create thread is not accepting the member functon

    - by prabhakaran
    I am trying to create a class for network programming. This will create a general purpose socket with thread. But when I tried to creat the thread using createthread(). The third argument is producing errors. And from the net I came to know that I can't use the member functions as a argument to the createthread(). Is there any thing by which I can achieve this.

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  • Need to know how to properly create a new object in another cpp file

    - by karikari
    I have a class. The problem now is, after a few attempt, I'm still in huge error. My problem is I don't know how to properly declare a new object for this class, inside another cpp file. I wanted to call/trigger the functions from this RebarHandler class from my other cpp file. I keep on getting problems like, 'used without being initialized', 'debug assertion failed' and so on. In the other cpp file, I include the RebarHandler.h and did like this: CRebarHandler *test=NULL; test->setButtonMenu2(); When compile, I does not give any error. But, when run time, it gives error and my IE crash. I need help. Below is the class I meant: #pragma once class CIEWindow; class CRebarHandler : public CWindowImpl<CRebarHandler>{ public: CRebarHandler(HWND hWndToolbar, CIEWindow *ieWindow); CRebarHandler(){}; ~CRebarHandler(); BEGIN_MSG_MAP(CRebarHandler) NOTIFY_CODE_HANDLER(TBN_DROPDOWN, onNotifyDropDown) NOTIFY_CODE_HANDLER(TBN_TOOLBARCHANGE, onNotifyToolbarChange) NOTIFY_CODE_HANDLER(NM_CUSTOMDRAW, onNotifyCustomDraw) NOTIFY_CODE_HANDLER(TBN_ENDADJUST, onNotifyEndAdjust) MESSAGE_HANDLER(WM_SETREDRAW, onSetRedraw) END_MSG_MAP() // message handlers LRESULT onNotifyDropDown(WPARAM wParam, LPNMHDR pNMHDR, BOOL& bHandled); LRESULT onNotifyToolbarChange(WPARAM wParam, LPNMHDR pNMHDR, BOOL& bHandled); LRESULT onNotifyCustomDraw(WPARAM wParam, LPNMHDR pNMHDR, BOOL& bHandled); LRESULT onNotifyEndAdjust(WPARAM wParam, LPNMHDR pNMHDR, BOOL& bHandled); LRESULT onSetRedraw(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled); // manage the subclassing of the IE rebar void subclass(); void unsubclass(); void handleSettings(); void setButtonMenu2(); bool findButton(HWND hWndToolbar); private: // handles to the various things HWND m_hWnd; HWND m_hWndToolbar, m_hWndRebar, m_hWndTooltip; HMENU m_hMenu; int m_buttonID; int m_ieVer; CIEWindow *m_ieWindow; // toolbar finding functions void scanForToolbarSlow(); void getRebarHWND(); void setButtonMenu(); };

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  • simple toggle problem

    - by meo
    I'm just programming a little function that toggles a content by fading it in and out. this.advancedSearch = function(fieldset, triggerBtn){ fieldset.hide() triggerBtn.click(function(){ fieldset.toggle(function(){ $(this).stop(false, true).fadeIn(300) }, function(){ $(this).stop(false, true).fadeIn(300) }) }) } if just I use toggle() it works, but when i insert the two functions nothing happens and no error is thrown. Is there something i have done wrong?

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  • Where are the function literals in c++?

    - by academicRobot
    First of all, maybe literals is not the right term for this concept, but its the closest I could think of (not literals in the sense of functions as first class citizens). The idea is that when you make a conventional function call, it compiles to something like this: callq <immediate address> But if you make a function call using a function pointer, it compiles to something like this: mov <memory location>,%rax callq *%rax Which is all well and good. However, what if I'm writing a template library that requires a callback of some sort with a specified argument list and the user of the library is expected to know what function they want to call at compile time? Then I would like to write my template to accept a function literal as a template parameter. So, similar to template <int int_literal> struct my_template {...};` I'd like to write template <func_literal_t func_literal> struct my_template {...}; and have calls to func_literal within my_template compile to callq <immediate address>. Is there a facility in C++ for this, or a work around to achieve the same effect? If not, why not (e.g. some cataclysmic side effects)? How about C++0x or another language? Solutions that are not portable are fine. Solutions that include the use of member function pointers would be ideal. I'm not particularly interested in being told "You are a <socially unacceptable term for a person of low IQ>, just use function pointers/functors." This is a curiosity based question, and it seems that it might be useful in some (albeit limited) applications. It seems like this should be possible since function names are just placeholders for a (relative) memory address, so why not allow more liberal use (e.g. aliasing) of this placeholder. p.s. I use function pointers and functions objects all the the time and they are great. But this post got me thinking about the don't pay for what you don't use principle in relation to function calls, and it seems like forcing the use of function pointers or similar facility when the function is known at compile time is a violation of this principle, though a small one.

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  • How do you return a pointer to a base class with a virtual function?

    - by Nick Sweet
    I have a base class called Element, a derived class called Vector, and I'm trying to redefine two virtual functions from Element in Vector. //element.h template <class T> class Element { public: Element(); virtual Element& plus(const Element&); virtual Element& minus(const Element&); }; and in another file //Vector.h #include "Element.h" template <class T> class Vector: public Element<T> { T x, y, z; public: //constructors Vector(); Vector(const T& x, const T& y = 0, const T& z =0); Vector(const Vector& u); ... //operations Element<T>& plus(const Element<T>& v) const; Element<T>& minus(const Element<T>& v) const; ... }; //sum template <class T> Element<T>& Vector<T>::plus(const Element<T>& v) const { Element<T>* ret = new Vector((x + v.x), (y + v.y), (z + v.z)); return *ret; } //difference template <class T> Element<T>& Vector<T>::minus(const Element<T>& v) const { Vector<T>* ret = new Vector((x - v.x), (y - v.y), (z - v.z)); return *ret; } but I always get error: 'const class Element' has no member named 'getx' So, can I define my virtual functions to take Vector& as an argument instead, or is there a way for me to access the data members of Vector through a pointer to Element? I'm still fairly new to inheritance polymorphism, fyi.

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  • How do I use multiple where clauses in GHCi?

    - by T.R.
    I'm playing around with GHCi for the first time, and I'm having some trouble writing multi-line functions. My code is as follows: Prelude> :{ Prelude| let diffSquares lst = abs $ squareOfSums lst - sumOfSquares lst Prelude| where Prelude| squareOfSums lst = (fst (sumsAndSquares lst))^2 Prelude| sumOfSquares lst = snd (sumsAndSquares lst) Prelude| sumsAndSquares = foldl (\(sms,sqrs) x -> (sms+x,sqrs+x^2)) (0,0) Prelude| :} It gives the following error: <interactive>:1:142: parse error on input `=' Could someone kindly point me in the direction of what I'm missing?

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  • Add text to every line in text file using PowerShell

    - by Joshua
    I'd like to add characters to the end of every line of text in a .txt document. #Define Variables $a = c:\foobar.txt $b = get-content $a #Define Functions function append-text { foreach-Object { add "*" } } #Process Code $b | append-text Something like that. Essentially, load a given text file, add a "*" the the end of every single line of text in that text file, save and close.

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