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  • EXC_BAD_ACCESS when I change moviePlayer contentURL

    - by Bruno
    Hello, In few words, my application is doing that : 1) My main view (MovieListController) has some video thumbnails and when I tap on one, it displays the moviePlayer (MoviePlayerViewController) : MovieListController.h : @interface MoviePlayerViewController : UIViewController <UITableViewDelegate>{ UIView *viewForMovie; MPMoviePlayerController *player; } @property (nonatomic, retain) IBOutlet UIView *viewForMovie; @property (nonatomic, retain) MPMoviePlayerController *player; - (NSURL *)movieURL; @end MovieListController.m : MoviePlayerViewController *controllerTV = [[MoviePlayerViewController alloc] initWithNibName:@"MoviePlayerViewController" bundle:nil]; controllerTV.delegate = self; controllerTV.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal; [self presentModalViewController: controllerTV animated: YES]; [controllerTV release]; 2) In my moviePlayer, I initialize the video I want to play MoviePlayerViewController.m : @implementation MoviePlayerViewController @synthesize player; @synthesize viewForMovie; - (void)viewDidLoad { NSLog(@"start"); [super viewDidLoad]; self.player = [[MPMoviePlayerController alloc] init]; self.player.view.frame = self.viewForMovie.bounds; self.player.view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight; [self.viewForMovie addSubview:player.view]; self.player.contentURL = [self movieURL]; } - (void)dealloc { NSLog(@"dealloc TV"); [player release]; [viewForMovie release]; [super dealloc]; } -(NSURL *)movieURL { NSBundle *bundle = [NSBundle mainBundle]; NSString *moviePath = [bundle pathForResource:@"FR_Tribord_Surf camp_100204" ofType:@"mp4"]; if (moviePath) { return [NSURL fileURLWithPath:moviePath]; } else { return nil; } } - It's working good, my movie is display My problem : When I go back to my main view : - (void) returnToMap: (MoviePlayerViewController *) controller { [self dismissModalViewControllerAnimated: YES]; } And I tap in a thumbnail to display again the moviePlayer (MoviePlayerViewController), I get a *Program received signal: “EXC_BAD_ACCESS”.* In my debugger I saw that it's stopping on the thread "main" : // // main.m // MoviePlayer // // Created by Eric Freeman on 3/27/10. // Copyright Apple Inc 2010. All rights reserved. // #import <UIKit/UIKit.h> int main(int argc, char *argv[]) { NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init]; int retVal = UIApplicationMain(argc, argv, nil, nil); //EXC_BAD_ACCESS [pool release]; return retVal; } If I comment self.player.contentURL = [self movieURL]; it's working, but when I let it, iI have this problem. I read that it's due to null pointer or memory problem but I don't understand why it's working the first time and not the second time. I release my object in dealloc method. Thanks for your help ! Bruno.

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  • Variable lenght arguments in log4cxx LOG4CXX_ macros

    - by Horacio
    I am using log4cxx in a big C++ project but I really don't like how log4cxx handles multiple variables when logging: LOG4CXX_DEBUG(logger, "test " << var1 << " and " << var3 " and .....) I prefer using printf like variable length arguments: LOG4CXX_DEBUG(logger, "test %d and %d", var1, var3) So I implemented this small wrapper on top of log4cxx #include <string.h> #include <stdio.h> #include <stdarg.h> #include <log4cxx/logger.h> #include "log4cxx/basicconfigurator.h" const char * log_format(const char *fmt, ...); #define MYLOG_TRACE(logger, fmt, ...) LOG4CXX_TRACE(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_DEBUG(logger, fmt, ...) LOG4CXX_DEBUG(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_INFO(logger, fmt, ...) LOG4CXX_INFO(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_WARN(logger, fmt, ...) LOG4CXX_WARN(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_ERROR(logger, fmt, ...) LOG4CXX_ERROR(logger, log_format(fmt, ## __VA_ARGS__)) #define MYLOG_FATAL(logger, fmt, ...) LOG4CXX_FATAL(logger, log_format(fmt, ## __VA_ARGS__)) static log4cxx::LoggerPtr logger(log4cxx::Logger::getRootLogger()); int main(int argc, char **argv) { log4cxx::BasicConfigurator::configure(); MYLOG_INFO(logger, "Start "); MYLOG_WARN(logger, log_format("In running this in %d threads safe?", 1000)); MYLOG_INFO(logger, "End "); return 0; } const char *log_format(const char *fmt, ...) { va_list va; static char formatted[1024]; va_start(va, fmt); vsprintf(formatted, 1024, fmt, va); va_end(va); return formatted; } And this works perfectly but I know using that static variable (formatted) can become problematic if I start using threads and each thread logging to the same place. I am no expert in log4cxx so I was wondering if the LOG4CXX macros are handling concurrent thread access automatically? or do I have to implement some sort of locking around the log_format method? something that I wan't to avoid due to performance implications. Also I would like to ask why if I replace the vsprintf inside the log_format method with vsnprintf (that is more secure) then I get nothing printed? To compile and test this program (in Ubuntu) use : g++ -o loggertest loggertest.cpp -llog4cxx

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  • Constructor or Explicit cast

    - by Felan
    In working with Linq to Sql I create a seperate class to ferry data to a web page. To simplify creating these ferry objects I either use a specialized constructor or an explicit conversion operator. I have two questions. First which approach is better from a readibility perspective? Second while the clr code that is generated appeared to be the same to me, are there situations where one would be treated different than the other by the compiler (in lambda's or such). Example code (DatabaseFoo uses specialized constructor and BusinessFoo uses explicit operator): public class DatabaseFoo { private static int idCounter; // just to help with generating data public int Id { get; set; } public string Name { get; set; } public DatabaseFoo() { Id = idCounter++; Name = string.Format("Test{0}", Id); } public DatabaseFoo(BusinessFoo foo) { this.Id = foo.Id; this.Name = foo.Name; } } public class BusinessFoo { public int Id { get; set; } public string Name { get; set; } public static explicit operator BusinessFoo(DatabaseFoo foo) { return FromDatabaseFoo(foo); } public static BusinessFoo FromDatabaseFoo(DatabaseFoo foo) { return new BusinessFoo {Id = foo.Id, Name = foo.Name}; } } public class Program { static void Main(string[] args) { Console.WriteLine("Creating the initial list of DatabaseFoo"); IEnumerable<DatabaseFoo> dafoos = new List<DatabaseFoo>() { new DatabaseFoo(), new DatabaseFoo(), new DatabaseFoo(), new DatabaseFoo(), new DatabaseFoo(), new DatabaseFoo()}; foreach(DatabaseFoo dafoo in dafoos) Console.WriteLine(string.Format("{0}\t{1}", dafoo.Id, dafoo.Name)); Console.WriteLine("Casting the list of DatabaseFoo to a list of BusinessFoo"); IEnumerable<BusinessFoo> bufoos = from x in dafoos select (BusinessFoo) x; foreach (BusinessFoo bufoo in bufoos) Console.WriteLine(string.Format("{0}\t{1}", bufoo.Id, bufoo.Name)); Console.WriteLine("Creating a new list of DatabaseFoo by calling the constructor taking BusinessFoo"); IEnumerable<DatabaseFoo> fufoos = from x in bufoos select new DatabaseFoo(x); foreach(DatabaseFoo fufoo in fufoos) Console.WriteLine(string.Format("{0}\t{1}", fufoo.Id, fufoo.Name)); } }

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  • Possible bug with tabified QDockWidget and setFloating()

    - by krunk
    I've run into some odd behavior with tabified QDockWidgets, below is an example program with comments that demonstrates the behavior. Is this a bug or is it expected behavior and I'm missing some nuance in QDockWidget that causes this? Directly, since this does not work, how would one properly "undock" a hidden QDockWidget then display it? #include <QApplication> #include <QMainWindow> #include <QAction> #include <QDockWidget> #include <QMenu> #include <QSize> #include <QMenuBar> using namespace std; int main (int argc, char* argv[]) { QApplication app(argc, argv); QMainWindow window; QDockWidget dock1(&window); QDockWidget dock2(&window); QMenu menu("View"); dock1.setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea); dock2.setAllowedAreas(Qt::LeftDockWidgetArea | Qt::RightDockWidgetArea); dock1.setWindowTitle("Dock One"); dock2.setWindowTitle("Dock Two"); window.addDockWidget(Qt::RightDockWidgetArea, &dock1); window.addDockWidget(Qt::RightDockWidgetArea, &dock2); window.menuBar()->addMenu(&menu); window.setMinimumSize(QSize(800, 600)); window.tabifyDockWidget(&dock1, &dock2); dock1.hide(); dock2.hide(); menu.addAction(dock1.toggleViewAction()); menu.addAction(dock2.toggleViewAction()); window.show(); // Below is where the oddness starts. It seems to only exhibit the // behavior if the dock widgets are tabified. // Odd behavior here // This does not work. the window never shows, though its menu action shows // checked. Not only does this window not show up, but all toggle actions // for all dock windows (e.g. dock1 and dock2) are broken for the duration // of the application loop. // dock1.setFloating(true); // dock1.show(); // This does work. . . of course only if you do _not_ run the above first. // however, you can often get a little lag or "blip" in the rendering as // the dock is shown docked before setFloating is set to true. dock1.show(); dock1.setFloating(true); return app.exec(); }

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  • I can't Open my excel file in c#

    - by Ruben Guico
    Hi, Below is my code, i tried to open my excel file in my c# application but the program give's me an error message "Cannot Access "my excel.xls". But when I specify the file path in my string path variable it works, the problem is I need to get the file path from an openFileDialog. using System; using System.IO; using System.Collections.Generic; using System.Text; using System.Data; using System.Windows.Forms; using System.Data.OleDb; using System.Reflection; using MOIE = Microsoft.Office.Interop.Excel; using OFFICE = Microsoft.Office.Core; namespace EmpUploader { public class ExcelCon { private OleDbDataReader reader = null; private OleDbCommand excelCommand = new OleDbCommand(); private OleDbDataAdapter adapter = new OleDbDataAdapter(); private DataTable excelData = new DataTable(); private MOIE.ApplicationClass objExcel = new MOIE.ApplicationClass(); private MOIE.Workbook wb = null; private string myConn = ""; private string strSQL = ""; private string err = ""; private string path2 = ""; private int sheetCount = 0; private OleDbConnection Con = new OleDbConnection(""); #region "excel interop prarameters" private static object xl_missing = Type.Missing; private static object xl_true = true; private static object xl_false = false; private object xl_update_links = xl_missing; private object xl_read_only = xl_missing; private object xl_format = xl_missing; private object xl_password = xl_missing; private object xl_write_res_password = xl_missing; private object xl_ignore_read_only = xl_missing; private object xl_origin = xl_missing; private object xl_delimiter = xl_missing; private object xl_editable = xl_missing; private object xl_notify = xl_missing; private object xl_converter = xl_missing; private object xl_add_to_mru = xl_missing; private object xl_local = xl_missing; private object xl_corrupt_load = xl_missing; #endregion } //MY CODE FOR OPENING THE EXCEL //note that my file path came from an openfiledialog public void InitializeConnection(string path) { //connection string for excel myConn = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + path + "; Extended Properties =Excel 8.0"; Con.ConnectionString = myConn; Con.Open(); //this is the sample specified path that worked when i test my application //path = @"C:\shinetsu p5 emp list.xls"; objExcel.Visible = false; wb = objExcel.Workbooks.Open(path, xl_update_links, xl_read_only, xl_format, xl_password, xl_write_res_password, xl_ignore_read_only, xl_origin, xl_delimiter, xl_editable, xl_notify, xl_converter, xl_add_to_mru, xl_local, xl_corrupt_load); sheetCount = wb.Worksheets.Count; } }

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  • Parallel For Loop - Problems when adding to a List - Possible .Net Bugs

    - by Kevin Crowell
    I am having some issues involving Parallel for loops and adding to a List. The problem is, the same code may generate different output at different times. I have set up some test code below. In this code, I create a List of 10,000 int values. 1/10th of the values will be 0, 1/10th of the values will be 1, all the way up to 1/10th of the values being 9. After setting up this List, I setup a Parallel for loop that iterates through the list. If the current number is 0, I add a value to a new List. After the Parallel for loop completes, I output the size of the list. The size should always be 1,000. Most of the time, the correct answer is given. However, I have seen 3 possible incorrect outcomes occur: The size of the list is less than 1,000 An IndexOutOfRangeException occurs @ doubleList.Add(0.0); An ArgumentException occurs @ doubleList.Add(0.0); The message for the ArgumentException given was: Destination array was not long enough. Check destIndex and length, and the array's lower bounds. What could be causing the errors? Is this a .Net bug? Is there something I can do to prevent this from happening? Please try the code for yourself. If you do not get an error, try it a few times. Please also note that you probably will not see any errors using a single-core machine. using System; using System.Collections.Generic; using System.Threading.Tasks; namespace ParallelTest { class Program { static void Main(string[] args) { List<int> intList = new List<int>(); List<double> doubleList = new List<double>(); for (int i = 0; i < 250; i++) { intList.Clear(); doubleList.Clear(); for (int j = 0; j < 10000; j++) { intList.Add(j % 10); } Parallel.For(0, intList.Count, j => { if (intList[j] == 0) { doubleList.Add(0.0); } }); if (doubleList.Count != 1000) { Console.WriteLine("On iteration " + i + ": List size = " + doubleList.Count); } } Console.WriteLine("\nPress any key to exit."); Console.ReadKey(); } } }

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  • Any tips on reducing wxWidgets application code size?

    - by Billy ONeal
    I have written a minimal wxWidgets application: stdafx.h #define wxNO_REGEX_LIB #define wxNO_XML_LIB #define wxNO_NET_LIB #define wxNO_EXPAT_LIB #define wxNO_JPEG_LIB #define wxNO_PNG_LIB #define wxNO_TIFF_LIB #define wxNO_ZLIB_LIB #define wxNO_ADV_LIB #define wxNO_HTML_LIB #define wxNO_GL_LIB #define wxNO_QA_LIB #define wxNO_XRC_LIB #define wxNO_AUI_LIB #define wxNO_PROPGRID_LIB #define wxNO_RIBBON_LIB #define wxNO_RICHTEXT_LIB #define wxNO_MEDIA_LIB #define wxNO_STC_LIB #include <wx/wxprec.h> Minimal.cpp #include "stdafx.h" #include <memory> #include <wx/wx.h> class Minimal : public wxApp { public: virtual bool OnInit(); }; IMPLEMENT_APP(Minimal) DECLARE_APP(Minimal) class MinimalFrame : public wxFrame { DECLARE_EVENT_TABLE() public: MinimalFrame(const wxString& title); void OnQuit(wxCommandEvent& e); void OnAbout(wxCommandEvent& e); }; BEGIN_EVENT_TABLE(MinimalFrame, wxFrame) EVT_MENU(wxID_ABOUT, MinimalFrame::OnAbout) EVT_MENU(wxID_EXIT, MinimalFrame::OnQuit) END_EVENT_TABLE() MinimalFrame::MinimalFrame(const wxString& title) : wxFrame(0, wxID_ANY, title) { std::auto_ptr<wxMenu> fileMenu(new wxMenu); fileMenu->Append(wxID_EXIT, L"E&xit\tAlt-X", L"Terminate the Minimal Example."); std::auto_ptr<wxMenu> helpMenu(new wxMenu); helpMenu->Append(wxID_ABOUT, L"&About\tF1", L"Show the about dialog box."); std::auto_ptr<wxMenuBar> bar(new wxMenuBar); bar->Append(fileMenu.get(), L"&File"); fileMenu.release(); bar->Append(helpMenu.get(), L"&Help"); helpMenu.release(); SetMenuBar(bar.get()); bar.release(); CreateStatusBar(2); SetStatusText(L"Welcome to wxWidgets!"); } void MinimalFrame::OnAbout(wxCommandEvent& e) { wxMessageBox(L"Some text about me!", L"About", wxOK, this); } void MinimalFrame::OnQuit(wxCommandEvent& e) { Close(); } bool Minimal::OnInit() { std::auto_ptr<MinimalFrame> mainFrame( new MinimalFrame(L"Minimal wxWidgets Application")); mainFrame->Show(); mainFrame.release(); return true; } This minimal program weighs in at 2.4MB! (Executable compression drops this to half a MB or so but that's still HUGE!) (I must statically link because this application needs to be single-binary-xcopy-deployed, so both the C runtime and wxWidgets itself are set for static linking) Any tips on cutting this down? (I'm using Microsoft Visual Studio 2010)

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  • How to do a search from a list with non-prefix keywords[Solved]

    - by aNui
    The Problem is Solved. Thanks for every answers. First of all, sorry if my english or my post got any mistakes. I am programming a program to search the name from the list and I need to find them even if the keyword is not in front of the names (that's what I mean non-prefix) e.g. if I my list is the music instruments and I type "guit" to the search textbox. It should find the names "Guitar, Guitarrón, Acoustic Guitar, Bass Guitar, ..." or something like this Longdo Dictionary's search suggestion. here is my simple and stupid algorithm (that's all I can do) const int SEARCHROWLIMIT = 30; private string[] DoSearch(string Input, string[] ListToSearch) { List<string> FoundNames = new List<string>(); int max = 0; bool over = false; for (int k = 0; !over; k++) { foreach (string item in ListToSearch) { max = (max > item.Length) ? max : item.Length; if (k > item.Length) continue; if (k >= max) { over = true; break; } if (!Input.Equals("Search") && item.Substring(k, item.Length - k).StartsWith(Input, StringComparison.OrdinalIgnoreCase)) { bool exist = false; int i = 0; while (!exist && i < FoundNames.Count) { if (item.Equals(FoundNames[i])) { exist = true; break; } i++; } if (!exist && FoundNames.Count < SEARCHROWLIMIT) FoundNames.Add(item); else if (FoundNames.Count >= SEARCHROWLIMIT) over = true; } } } return FoundNames.ToArray(); } I think this algorithm is too slow for a large number of names and after several trial-and-error, I decided to add SEARCHROWLIMIT to breaks the operation And I also think there're some readymade methods that can do that. And another problem is I need to search music instruments by a category like strings, percussions, ... and by the country of origins. So I need to search them with filter by type and country. please help me. P.S. Me and my friends are just student from Thailand and developing the project to compete in Microsoft Imagine Cup 2010 and please become fan on our facebook page [KRATIB][3]. And we're so sorry we don't have much information in English but you can talk to us in English.

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  • Problem compiling c++ in CodeGear

    - by Carlos
    I have written a C++ program for a University assignment. I used Netbeans 6.8 running on my Mac and the code runs smoothly, no warnings, errors or problems/bugs. However when compiling and running on a Windows computer using CodeGear RAD Studio 2009 (C++ Builder) am getting several errors. [BCC32 Error] main.cpp(51): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(62): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(67): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(112): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(121): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(130): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(133): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(139): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(153): E2094 'operator<<' not implemented in type 'fstream' for arguments of type 'string' [BCC32 Error] main.cpp(199): E2094 'operator>>' not implemented in type 'fstream' for arguments of type 'string' [BCC32 Error] main.cpp(219): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(231): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(240): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(262): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(264): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' These are the header files am using #include <iostream> #include <fstream> #include <cmath> #include <stdio> #include <windows> //I added this one just to check and still does not work (I didnt have it on Netbeans/Mac) using namespace std; Any ideas what is producing the errors and how can I fix it?

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  • Performance of looping over an Unboxed array in Haskell

    - by Joey Adams
    First of all, it's great. However, I came across a situation where my benchmarks turned up weird results. I am new to Haskell, and this is first time I've gotten my hands dirty with mutable arrays and Monads. The code below is based on this example. I wrote a generic monadic for function that takes numbers and a step function rather than a range (like forM_ does). I compared using my generic for function (Loop A) against embedding an equivalent recursive function (Loop B). Having Loop A is noticeably faster than having Loop B. Weirder, having both Loop A and B together is faster than having Loop B by itself (but slightly slower than Loop A by itself). Some possible explanations I can think of for the discrepancies. Note that these are just guesses: Something I haven't learned yet about how Haskell extracts results from monadic functions. Loop B faults the array in a less cache efficient manner than Loop A. Why? I made a dumb mistake; Loop A and Loop B are actually different. Note that in all 3 cases of having either or both Loop A and Loop B, the program produces the same output. Here is the code. I tested it with ghc -O2 for.hs using GHC version 6.10.4 . import Control.Monad import Control.Monad.ST import Data.Array.IArray import Data.Array.MArray import Data.Array.ST import Data.Array.Unboxed for :: (Num a, Ord a, Monad m) => a -> a -> (a -> a) -> (a -> m b) -> m () for start end step f = loop start where loop i | i <= end = do f i loop (step i) | otherwise = return () primesToNA :: Int -> UArray Int Bool primesToNA n = runSTUArray $ do a <- newArray (2,n) True :: ST s (STUArray s Int Bool) let sr = floor . (sqrt::Double->Double) . fromIntegral $ n+1 -- Loop A for 4 n (+ 2) $ \j -> writeArray a j False -- Loop B let f i | i <= n = do writeArray a i False f (i+2) | otherwise = return () in f 4 forM_ [3,5..sr] $ \i -> do si <- readArray a i when si $ forM_ [i*i,i*i+i+i..n] $ \j -> writeArray a j False return a primesTo :: Int -> [Int] primesTo n = [i | (i,p) <- assocs . primesToNA $ n, p] main = print $ primesTo 30000000

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  • How to generate and encode (for use in GA), random, strict, binary rooted trees with N leaves?

    - by Peter Simon
    First, I am an engineer, not a computer scientist, so I apologize in advance for any misuse of nomenclature and general ignorance of CS background. Here is the motivational background for my question: I am contemplating writing a genetic algorithm optimizer to aid in designing a power divider network (also called a beam forming network, or BFN for short). The BFN is intended to distribute power to each of N radiating elements in an array of antennas. The fraction of the total input power to be delivered to each radiating element has been specified. Topologically speaking, a BFN is a strictly binary, rooted tree. Each of the (N-1) interior nodes of the tree represents the input port of an unequal, binary power splitter. The N leaves of the tree are the power divider outputs. Given a particular power divider topology, one is still free to map the power divider outputs to the array inputs in an arbitrary order. There are N! such permutations of the outputs. There are several considerations in choosing the desired ordering: 1) The power ratio for each binary coupler should be within a specified range of values. 2) The ordering should be chosen to simplify the mechanical routing of the transmission lines connecting the power divider. The number of ouputs N of the BFN may range from, say, 6 to 22. I have already written a genetic algorithm optimizer that, given a particular BFN topology and desired array input power distribution, will search through the N! permutations of the BFN outputs to generate a design with compliant power ratios and good mechanical routing. I would now like to generalize my program to automatically generate and search through the space of possible BFN topologies. As I understand it, for N outputs (leaves of the binary tree), there are $C_{N-1}$ different topologies that can be constructed, where $C_N$ is the Catalan number. I would like to know how to encode an arbitrary tree having N leaves in a way that is consistent with a chromosomal description for use in a genetic algorithm. Also associated with this is the need to generate random instances for filling the initial population, and to implement crossover and mutations operators for this type of chromosome. Any suggestions will be welcome. Please minimize the amount of CS lingo in your reply, since I am not likely to be acquainted with it. Thanks in advance, Peter

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  • Code-Golf: Friendly Number Abbreviator

    - by David Murdoch
    Based on this question: Is there a way to round numbers into a friendly format? THE CHALLENGE - UPDATED! (removed hundreds abbreviation from spec) The shortest code by character count that will abbreviate an integer (no decimals). Code should include the full program. Relevant range is from 0 - 9,223,372,036,854,775,807 (the upper limit for signed 64 bit integer). The number of decimal places for abbreviation will be positive. You will not need to calculate the following: 920535 abbreviated -1 place (which would be something like 0.920535M). Numbers in the tens and hundreds place (0-999) should never be abbreviated (the abbreviation for the number 57 to 1+ decimal places is 5.7dk - it is unneccessary and not friendly). Remember to round half away from zero (23.5 gets rounded to 24). Banker's rounding is verboten. Here are the relevant number abbreviations: h = hundred (102) k = thousand (103) M = million (106) G = billion (109) T = trillion (1012) P = quadrillion (1015) E = quintillion (1018) SAMPLE INPUTS/OUTPUTS (inputs can be passed as separate arguments): First argument will be the integer to abbreviate. The second is the number of decimal places. 12 1 => 12 // tens and hundreds places are never rounded 1500 2 => 1.5k 1500 0 => 2k // look, ma! I round UP at .5 0 2 => 0 1234 0 => 1k 34567 2 => 34.57k 918395 1 => 918.4k 2134124 2 => 2.13M 47475782130 2 => 47.48G 9223372036854775807 3 => 9.223E // ect... . . . Original answer from related question (javascript, does not follow spec): function abbrNum(number, decPlaces) { // 2 decimal places => 100, 3 => 1000, etc decPlaces = Math.pow(10,decPlaces); // Enumerate number abbreviations var abbrev = [ "k", "m", "b", "t" ]; // Go through the array backwards, so we do the largest first for (var i=abbrev.length-1; i>=0; i--) { // Convert array index to "1000", "1000000", etc var size = Math.pow(10,(i+1)*3); // If the number is bigger or equal do the abbreviation if(size <= number) { // Here, we multiply by decPlaces, round, and then divide by decPlaces. // This gives us nice rounding to a particular decimal place. number = Math.round(number*decPlaces/size)/decPlaces; // Add the letter for the abbreviation number += abbrev[i]; // We are done... stop break; } } return number; }

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  • What's a clean way to break up a DataTable into chunks of a fixed size with Linq?

    - by Michael Haren
    Update: Here's a similar question Suppose I have a DataTable with a few thousand DataRows in it. I'd like to break up the table into chunks of smaller rows for processing. I thought C#3's improved ability to work with data might help. This is the skeleton I have so far: DataTable Table = GetTonsOfData(); // Chunks should be any IEnumerable<Chunk> type var Chunks = ChunkifyTableIntoSmallerChunksSomehow; // ** help here! ** foreach(var Chunk in Chunks) { // Chunk should be any IEnumerable<DataRow> type ProcessChunk(Chunk); } Any suggestions on what should replace ChunkifyTableIntoSmallerChunksSomehow? I'm really interested in how someone would do this with access C#3 tools. If attempting to apply these tools is inappropriate, please explain! Update 3 (revised chunking as I really want tables, not ienumerables; going with an extension method--thanks Jacob): Final implementation: Extension method to handle the chunking: public static class HarenExtensions { public static IEnumerable<DataTable> Chunkify(this DataTable table, int chunkSize) { for (int i = 0; i < table.Rows.Count; i += chunkSize) { DataTable Chunk = table.Clone(); foreach (DataRow Row in table.Select().Skip(i).Take(chunkSize)) { Chunk.ImportRow(Row); } yield return Chunk; } } } Example consumer of that extension method, with sample output from an ad hoc test: class Program { static void Main(string[] args) { DataTable Table = GetTonsOfData(); foreach (DataTable Chunk in Table.Chunkify(100)) { Console.WriteLine("{0} - {1}", Chunk.Rows[0][0], Chunk.Rows[Chunk.Rows.Count - 1][0]); } Console.ReadLine(); } static DataTable GetTonsOfData() { DataTable Table = new DataTable(); Table.Columns.Add(new DataColumn()); for (int i = 0; i < 1000; i++) { DataRow Row = Table.NewRow(); Row[0] = i; Table.Rows.Add(Row); } return Table; } }

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  • Creating and writing file from a FileOutputStream in Java

    - by Althane
    Okay, so I'm working on a project where I use a Java program to initiate a socket connection between two classes (a FileSender and FileReceiver). My basic idea was that the FileSender would look like this: try { writer = new DataOutputStream(connect.getOutputStream()); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } //While we have bytes to send while(filein.available() >0){ //We write them out to our buffer writer.write(filein.read(outBuffer)); writer.flush(); } //Then close our filein filein.close(); //And then our socket; connect.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); The constructor contains code that checks to see if the file exists, and that the socket is connected, and so on. Inside my FileReader is this though: input = recvSocket.accept(); BufferedReader br = new BufferedReader(new InputStreamReader(input.getInputStream())); FileOutputStream fOut= new FileOutputStream(filename); String line = br.readLine(); while(line != null){ fOut.write(line.getBytes()); fOut.flush(); line = br.readLine(); } System.out.println("Before RECV close statements"); fOut.close(); input.close(); recvSocket.close(); System.out.println("After RECV clsoe statements"); All inside a try-catch block. So, what I'm trying to do is have the FileSender reading in the file, converting to bytes, sending and flushing it out. FileReceiver, then reads in the bytes, writes to the fileOut, flushes, and continues waiting for more. I make sure to close all the things that I open, so... here comes the weird part. When I try and open the created text file in Eclipse, it tells me "An SWT error has occured ... recommended to exit the workbench... see .log for more details.". Another window pops up saying "Unhandled event loop exception, (no more handles)". However, if I try to open the sent text file in notepad2, I get ThisIsASentTextfile Which is good (well, minus the fact that there should be line breaks, but I'm working on that...). Does anyone know why this is happening? And while we're checking, how to add the line breaks? (And is this a particularly bad way to transfer files over java without getting some other libraries?)

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  • XNA - Mouse coordinates to word space transformation

    - by Gabriel Butcher
    I have a pretty annoying problem. I would like to create a drawing program, using winform + XNA combo. The most important part would be to transform the mouse position into the XNA drawn grid - I was able to make it for the translations, but it only work if I don't zoom in - when I do, the coordinates simply went horrible wrong. And I have no idea what I doing wrong. I tried to transform with scaling matrix, transform with inverse scaling matrix, multiplying with zoom, but none seems to work. In the beginning (with zoom value = 1) the grid starts from (0,0,0) going to (Width, Height, 0). I was able to get coordinates based on this grid as long as the zoom value didn't changed at all. I using a custom shader, with orthographic projection matrix, identity view matrix, and the transformed world matrix. Here is the two main method: internal void Update(RenderData data) { KeyboardState keyS = Keyboard.GetState(); MouseState mouS = Mouse.GetState(); if (ButtonState.Pressed == mouS.RightButton) { camTarget.X -= (float)(mouS.X - oldMstate.X) / 2; camTarget.Y += (float)(mouS.Y - oldMstate.Y) / 2; } if (ButtonState.Pressed == mouS.MiddleButton || keyS.IsKeyDown(Keys.Space)) { zVal += (float)(mouS.Y - oldMstate.Y) / 10; zoom = (float)Math.Pow(2, zVal); } oldKState = keyS; oldMstate = mouS; world = Matrix.CreateTranslation(new Vector3(-camTarget.X, -camTarget.Y, 0)) * Matrix.CreateScale(zoom / 2); } internal PointF MousePos { get { Vector2 mousePos = new Vector2(Mouse.GetState().X, Mouse.GetState().Y); Matrix trans = Matrix.CreateTranslation(new Vector3(camTarget.X - (Width / 2), -camTarget.Y + (Height / 2), 0)); mousePos = Vector2.Transform(mousePos, trans); return new PointF(mousePos.X, mousePos.Y); } } The second method should return the coordinates of the mouse cursor based on the grid (where the (0,0) point of the grid is the top-left corner.). But is just don't work. I deleted the zoom transformation from the matrix trans, as I didnt was able to get any useful result (most of the time, the coordinates was horrible wrong, mostly many thousand when the grid's size is 500x500). Any idea, or suggestion? I trying to solve this simple problem for two days now :\

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  • Unselecting RadioButtons in Java Swing

    - by Thomas
    When displaying a group of JRadioButtons, initially none of them is selected (unless you programmatically enforce that). I would like to be able to put buttons back into that state even after the user already selected one, i.e., none of the buttons should be selected. However, using the usual suspects doesn't deliver the required effect: calling 'setSelected(false)' on each button doesn't work. Interestingly, it does work when the buttons are not put into a ButtonGroup - unfortunately, the latter is required for JRadioButtons to be mutually exclusive. Also, using the setSelected(ButtonModel, boolean) - method of javax.swing.ButtonGroup doesn't do what I want. I've put together a small program to demonstrate the effect: two radio buttons and a JButton. Clicking the JButton should unselect the radio buttons so that the window looks exactly as it does when it first pops up. import java.awt.Container; import java.awt.GridLayout; import java.awt.event.*; import javax.swing.*; /** * This class creates two radio buttons and a JButton. Initially, none * of the radio buttons is selected. Clicking on the JButton should * always return the radio buttons into that initial state, i.e., * should disable both radio buttons. */ public class RadioTest implements ActionListener { /* create two radio buttons and a group */ private JRadioButton button1 = new JRadioButton("button1"); private JRadioButton button2 = new JRadioButton("button2"); private ButtonGroup group = new ButtonGroup(); /* clicking this button should unselect both button1 and button2 */ private JButton unselectRadio = new JButton("Unselect radio buttons."); /* In the constructor, set up the group and event listening */ public RadioTest() { /* put the radio buttons in a group so they become mutually * exclusive -- without this, unselecting actually works! */ group.add(button1); group.add(button2); /* listen to clicks on 'unselectRadio' button */ unselectRadio.addActionListener(this); } /* called when 'unselectRadio' is clicked */ public void actionPerformed(ActionEvent e) { /* variant1: disable both buttons directly. * ...doesn't work */ button1.setSelected(false); button2.setSelected(false); /* variant2: disable the selection via the button group. * ...doesn't work either */ group.setSelected(group.getSelection(), false); } /* Test: create a JFrame which displays the two radio buttons and * the unselect-button */ public static void main(String[] args) { JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); RadioTest test = new RadioTest(); Container contentPane = frame.getContentPane(); contentPane.setLayout(new GridLayout(3,1)); contentPane.add(test.button1); contentPane.add(test.button2); contentPane.add(test.unselectRadio); frame.setSize(400, 400); frame.setVisible(true); } } Any ideas anyone? Thanks!

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  • How could I send live video stream to remote server from my phone !!!

    - by poc
    Hello , I have a problem about streaming my video to server in real-time from my phone. that is , let my phone be a IP Camera , and server can watch the live video from my phone I have googled many many solutions, but there is no one can solve my problem. I use MediaRecorder to record . it can save video file in the SD card correctly. then , I refered this page and used some method as followings skt = new Socket(InetAddress.getByName(hostname),port); pfd =ParcelFileDescriptor.fromSocket(skt); mediaRecorder.setOutputFile(pfd.getFileDescriptor()); now it seems I can send the video stream while recording however, I wrote a receiver-side program to receive the video stream from Android , but it doesn't work . is there any error? I can receive file , but I can not open the video file . I guess the problem may caused by file format ? there are outline of my code. in android side Socket skt = new Socket(hostIP,port); ParcelFileDescriptor pfd =ParcelFileDescriptor.fromSocket(skt); .... .... mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); mediaRecorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT); mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4); mediaRecorder.setOutputFile(pfd.getFileDescriptor()); ..... mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT); mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP); ..... mediaRecorder.start(); in receiver side (my ACER notebook) // anyway , I don't think the file extentions will do any effect File video = new File (strDate+".3gpp"); FileOutputStream fos; try { fos = new FileOutputStream(video); byte[] data = new byte[1024]; int count =-1; while( (count = fin.read(data,0,1024) ) !=-1) { fos.write(data,0,count); fos.flush(); } fos.close(); fin.close(); I confused a long time.... thanks in advance

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  • Create class instance in assembly from string name

    - by Arcadian
    I'm not sure if this is possible, and I'm quite new to using assemblies in C#.NET. What I would like to do is to create an instance of a class when supplied the string name of that class. Something like this: using MyAssembly; namespace MyNameSpace { Class MyClass { int MyValue1; int MyValue2; public MyClass(string myTypeName) { foreach(Type type in MyAssembly) { if((string)type == myTypeName) { //create a new instance of the type } } AssignInitialValues(//the type created above) } //Here I use an abstract type which the type above inherits from private void AssignInitialValues(AbstractType myClass) { this.value1 = myClass.value1; this.value2 = myClass.value2; } } } Obviously you cannot compare strings to types but it illustrates what I'm trying to do: create a type from a supplied string. Any thoughts? EDIT: After attempting: var myObject = (AbstractType) Activator.CreateInstance(null, myTypeName); AssignInitialValues(myObject); I get a number of errors: Inconsistent accessibility: parameter type 'MyAssembly.AbstractType' is less accessible than method 'MyNameSpace.MyClass.AssignInitialValues(MyAssembly.AstractType)' 'MyAssembly.AstractType' is inaccessible due to it's protection level The type or namespace name 'MyAssembly' could not be found (are you missing a using directive or an assembly reference?) The type or namespace name 'AbstractType' could not be found (are you missing a using directive or an assembly reference?) Not exactly sure why it can't find the assembly; I've added a reference to the assembly and I use a Using Directive for the namespace in the assembly. As for the protection level, it's calling classes (or rather the constructors of classes) which can only be public. Any clues on where the problem is? UPDATE: After looking through several articles on SO I came across this: http://stackoverflow.com/a/1632609/360627 Making the AbstractTypeclass public solved the issue of inconsistent accessibility. The new compiler error is this: Cannot convert type 'System.Runtime.Remoting.ObjectHandle' to 'MyAssembly.AbstractType' The line it references is this one: var myObject = (AbstractType) Activator.CreateInstance(null, myTypeName); Using .Unwrap() get's me past this error and I think it's the right way to do it (uncertain). However, when running the program I then get a TypeLoadException when this code is called. TypeLoadException: Could not load type ‘AbstractType’ from assembly ‘MyNameSpace'... Right away I can spot that the type its looking for is correct but the assembly it's looking in is wrong. Looking up the Activator.CreateInstance(String, String) method revealed that the null as the first argument means that the method will look in the executing assembly. This is contrary to the required behavior as in the original post. I've tried using MyAssembly as the first argument but this produces the error: 'MyAssembly' is a 'namespace' but is used like a 'variable' Any thoughts on how to fix this?

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  • Best method for converting several sets of numbers with several different ratios

    - by C Patton
    I'm working on an open-source harm reduction application for opioid addicts. One of the features in this application is the conversion (in mg/mcg) between common opioids, so people don't overdose by accident. If you're morally against opioid addiction and wouldn't respond because of your morals, please consider that this application is for HARM REDUCTION.. So people don't end up dead. I have this data.. 3mg morphine IV = 10mcg fentanyl IV 2mg morphine oral = 1mg oxycodone oral 3mg oral morphine = 1mg oxymorphone oral 7.0mg morphine oral = 1mg hydromorphone oral 1mg morphine iv = .10mg oxymorphone iv 1mg morphine oral = 1mg hydrocodone oral 1mg morphine oral = 6.67mg codeine oral 1mg morphine oral = .10mg methadone oral And I have a textbox that is the source dosage in mg (a double) that the user can enter in. Underneath this, I have radio boxes for the source substance (ie: morphine) and the destination substance (ie oxycodone) for conversion.. I've been trying to think of the most efficient way to do this, but nearly every seems sloppy. If I were to do something like public static double MorphinetoOxycodone(string morphineValue) { double morphine = Double.Parse(morphineValue); return (morphine / 2 ); } I would also have to make a function for OxycodonetoMorphine, OxycodonetoCodeine, etc.. and then would end up with dozens functions.. There must be an easier way than this that I'm missing. If you'll notice, all of my conversions use morphine as the base value.. what might be the easiest way to use the morphine value to convert one opioid to another? For example, if 1mg morphine oral is equal to 1mg hydrocodone and 1mg morphine oral is equal to .10mg methadone, wouldn't I just multiply 1*.10 to get the hydrocodone-methadone value? Implementing this idea is what I'm having the most trouble with. Any help would be GREATLY appreciated.. and if you'd like, I would add your name/nickname to the credits in this program. It's possible that many, many people around the world will use this (I'm translating it into several languages as well) and to know that your work could've helped an addict from dying.. I think that's a great thing :) -cory

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  • Validate an Xml file against a DTD with a proxy. C# 2.0

    - by Chris Dunaway
    I have looked at many examples for validating an XML file against a DTD, but have not found one that allows me to use a proxy. I have a cXml file as follows (abbreviated for display) which I wish to validate: <?xml version="1.0" encoding="utf-8"?> <!DOCTYPE cXML SYSTEM "http://xml.cxml.org/schemas/cXML/1.2.018/InvoiceDetail.dtd"> <cXML payloadID="123456" timestamp="2009-12-10T10:05:30-06:00"> <!-- content snipped --> </cXML> I am trying to create a simple C# program to validate the xml against the DTD. I have tried code such as the following but cannot figure out how to get it to use a proxy: private static bool isValid = false; static void Main(string[] args) { try { XmlTextReader r = new XmlTextReader(args[0]); XmlReaderSettings settings = new XmlReaderSettings(); XmlDocument doc = new XmlDocument(); settings.ProhibitDtd = false; settings.ValidationType = ValidationType.DTD; settings.ValidationEventHandler += new ValidationEventHandler(v_ValidationEventHandler); XmlReader validator = XmlReader.Create(r, settings); while (validator.Read()) ; validator.Close(); // Check whether the document is valid or invalid. if (isValid) Console.WriteLine("Document is valid"); else Console.WriteLine("Document is invalid"); } catch (Exception ex) { Console.WriteLine(ex.ToString()); } } static void v_ValidationEventHandler(object sender, ValidationEventArgs e) { isValid = false; Console.WriteLine("Validation event\n" + e.Message); } The exception I receive is System.Net.WebException: The remote server returned an error: (407) Proxy Authentication Required. which occurs on the line while (validator.Read()) ; I know I can validate against a DTD locally, but I don't want to change the xml DOCTYPE since that is what the final form needs to be (this app is solely for diagnostic purposes). For more information about the cXML spec, you can go to cxml.org. I appreciate any assistance. Thanks

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  • binary files writing/reading problems...

    - by ScReYm0
    Ok i have problem with my code for reading binary file... First i will show you my writing code: void book_saving(char *file_name, struct BOOK *current) { FILE *out; BOOK buf; out = fopen(file_name, "wb"); if(out != NULL) { printf_s("Writting to file..."); do { if(current != NULL) { strcpy(buf.catalog_number, current-catalog_number); strcpy(buf.author, current-author); buf.price = current-price; strcpy(buf.publisher, current-publisher); strcpy(buf.title, current-title); buf.price = current-year_published; fwrite(&buf, sizeof(BOOK), 1, out); } current = current-next; }while(current != NULL); printf_s("Done!\n"); fclose(out); } } and here is my "version" for reading: int book_open(struct BOOK *current, char *file_name) { FILE *in; BOOK buf; BOOK *vnext; int count; int i; in = fopen("west", "rb"); printf_s("Reading database from %s...", file_name); if(!in) { printf_s("\nERROR!"); return 1; } i = fread(&buf,sizeof(BOOK), 1, in); while(!feof(in)) { if(current != NULL) { current = malloc(sizeof(BOOK)); current-next = NULL; } strcpy(current-catalog_number, buf.catalog_number); strcpy(current-title, buf.title); strcpy(current-publisher, buf.publisher); current-price = buf.price; current-year_published = buf.year_published; fread(&buf, 1, sizeof(BOOK), in); while(current-next != NULL) current = current-next; fclose(in); } printf_s("Done!"); return 0; } I just need to save my linked list in binary file and to be able to read it back ... please help me. The program just don't read it or its crash every time different situation ...

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  • Bracketing algorithm when root finding. Single root in "quadratic" function

    - by Ander Biguri
    I am trying to implement a root finding algorithm. I am using the hybrid Newton-Raphson algorithm found in numerical recipes that works pretty nicely. But I have a problem in bracketing the root. While implementing the root finding algorithm I realised that in several cases my functions have 1 real root and all the other imaginary (several of them, usually 6 or 9). The only root I am interested is in the real one so the problem is not there. The thing is that the function approaches the root like a cubic function, touching with the point the y=0 axis... Newton-Rapson method needs some brackets of different sign and all the bracketing methods I found don't work for this specific case. What can I do? It is pretty important to find that root in my program... EDIT: more problems: sometimes due to reaaaaaally small numerical errors, say a variation of 1e-6 in some value the "cubic" function does NOT have that real root, it is just imaginary with a neglectable imaginary part... (checked with matlab) EDIT 2: Much more information about the problem. Ok, I need root finding algorithm. Info I have: The root I need to find is between [0-1] , if there are more roots outside that part I am not interested in them. The root is real, there may be imaginary roots, but I don't want them. Probably all the rest of the roots will be imaginary The root may be double in that point, but I think that actually doesn't mater in numerical analysis problems I need to use the root finding algorithm several times during the overall calculations, but the function will always be a polynomial In one of the particular cases of the root finding, my polynomial will be similar to a quadratic function that touches Y=0 with the point. Example of a real case: The coefficient may not be 100% precise and that really slight imprecision may make the function not to touch the Y=0 axis. I cannot solve for this specific case because in other cases it may be that the polynomial is pretty normal and doesn't make any "strange" thing. The method I am actually using is NewtonRaphson hybrid, where if the derivative is really small it makes a bisection instead of NewRaph (found in numerical recipes). Matlab's answer to the function on the image: roots: 0.853553390593276 + 0.353553390593278i 0.853553390593276 - 0.353553390593278i 0.146446609406726 + 0.353553390593273i 0.146446609406726 - 0.353553390593273i 0.499999999999996 + 0.000000040142134i 0.499999999999996 - 0.000000040142134i The function is a real example I prepared where I know that the answer I want is 0.5 Note: I still haven't check completely some of the answers I you people have give me (Thank you!), I am just trying to give al the information I already have to complete the question.

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  • Design Technique: How to design a complex system for processing orders, products and units.

    - by Shyam
    Hi, Programming is fun: I learned that by trying out simple challenges, reading up some books and following some tutorials. I am able to grasp the concepts of writing with OO (I do so in Ruby), and write a bit of code myself. What bugs me though is that I feel re-inventing the wheel: I haven't followed an education or found a book (a free one that is) that explains me the why's instead of the how's, and I've learned from the A-team that it is the plan that makes it come together. So, armed with my nuby Ruby skills, I decided I wanted to program a virtual store. I figured out the following: My virtual Store will have: Products and Services Inventories Orders and Shipping Customers Now this isn't complex at all. With the help of some cool tools (CMapTools), I drew out some concepts, but quickly enough (thanks to my inferior experience in designing), my design started to bite me. My very first product-line were virtual "laptops". So, I created a class (Ruby): class Product attr_accessor :name, :price def initialize(name, price) @name = name @price = price end end which can be instantiated by doing (IRb) x = Product.new("Banana Pro", 250) Since I want my virtual customers to be able to purchase more than one product, or various types, I figured out I needed some kind of "Order" mechanism. class Order def initialize(order_no) @order_no = order_no @line_items = [] end def add_product(myproduct) @line_items << myproduct end def show_order() puts @order_no @line_items.each do |x| puts x.name.to_s + "\t" + x.price.to_s end end end that can be instantiated by doing (IRb) z = Order.new(1234) z.add_product(x) z.show_order Splendid, I have now a very simple ordering system that allows me to add products to an order. But, here comes my real question. What if I have three models of my product (economy, business, showoff)? Or have my products be composed out of separate units (bigger screen, nicer keyboard, different OS)? Surely I could make them three separate products, or add complexity to my product class, but I am looking for are best practices to design a flexible product object that can be used in the real world, to facilitate a complex system. My apologies if my grammar and my spelling are with error, as english is not my first language and I took the time to check as far I could understand and translate properly! Thank you for your answers, comments and feedback!

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  • Cpp some basic problems

    - by DevAno1
    Hello. My task was as follows : Create class Person with char*name and int age. Implement contructor using dynamic allocation of memory for variables, destructor, function init and friend function show. Then transform this class to header and cpp file and implement in other program. Ok so I've almost finished my Person class, but I get error after destructor. First question is how to write this properly ? #include <iostream> using namespace std; class Person { char* name; int age; public: int * take_age(); Person(){ int size=0; cout << "Give length of char*" << endl; cin >> size; name = new char[size]; age = 0; } ~Person(){ cout << "Destroying resources" << endl; delete *[] name; delete * take_age(); } friend void(Person &p); int * Person::take_age(){ return age; } void init(char* n, int a) { name = n; age = a; } void show(Person &p){ cout << "Name: " << p.name << "," << "age: " << p.age << endl; } }; int main(void) { Person *p = new Person; p->init("Mary", 25); p.show(); system("PAUSE"); return 0; } And now with header/implementation part : - do I need to introduce constructor in header/implementation files ? If yes - how? - my show() function is a friendly function. Should I take it into account somehow ? I already failed to return this task on my exam, but still I'd like to know how to implement it.

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  • Working through exercises in "Cocoa Programming for Mac OS X" - I'm stumped

    - by Zigrivers
    I've been working through the exercises in a book recommended here on stackoverflow, however I've run into a problem and after three days of banging my head on the wall, I think I need some help. I'm working through the "Speakline" exercise where we add a TableView to the interface and the table will display the "voices" that you can choose for the text to speech aspect of the program. I am having two problems that I can't seem to get to the bottom of: I get the following error: * Illegal NSTableView data source (). Must implement numberOfRowsInTableView: and tableView:objectValueForTableColumn:row: The tableView that is supposed to display the voices comes up blank I have a feeling that both of these problems are related. I'm including my interface code here: #import <Cocoa/Cocoa.h> @interface AppController : NSObject <NSSpeechSynthesizerDelegate, NSTableViewDelegate> { IBOutlet NSTextField *textField; NSSpeechSynthesizer *speechSynth; IBOutlet NSButton *stopButton; IBOutlet NSButton *startButton; IBOutlet NSTableView *tableView; NSArray *voiceList; } - (IBAction)sayIt:(id)sender; - (IBAction)stopIt:(id)sender; @end And my implementation code here: #import "AppController.h" @implementation AppController - (id)init { [super init]; //Log to help me understand what is happening NSLog(@"init"); speechSynth = [[NSSpeechSynthesizer alloc] initWithVoice:nil]; [speechSynth setDelegate:self]; voiceList = [[NSSpeechSynthesizer availableVoices] retain]; return self; } - (IBAction)sayIt:(id)sender { NSString *string = [[textField stringValue] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]]; //Is the string zero-length? if([string length] == 0) { NSLog(@"String from %@ is a string with a length of %d.", textField, [string length]); [speechSynth startSpeakingString:@"Please enter a phrase first."]; } [speechSynth startSpeakingString:string]; NSLog(@"Started to say: %@", string); [stopButton setEnabled:YES]; [startButton setEnabled:NO]; } - (IBAction)stopIt:(id)sender { NSLog(@"Stopping..."); [speechSynth stopSpeaking]; } - (void) speechSynthesizer:(NSSpeechSynthesizer *)sender didFinishSpeaking:(BOOL)complete { NSLog(@"Complete = %d", complete); [stopButton setEnabled:NO]; [startButton setEnabled:YES]; } - (NSInteger)numberOfRowsInTableView:(NSTableView *)aTableView { return [voiceList count]; } - (id)tableView: (NSTableView *)tv objecValueForTableColumn: (NSTableColumn *)tableColumn row:(NSInteger)row { NSString *v = [voiceList objectAtIndex:row]; NSLog(@"v = %@",v); NSDictionary *dict = [NSSpeechSynthesizer attributesForVoice:v]; return [dict objectForKey:NSVoiceName]; } /* - (BOOL)respondsToSelector:(SEL)aSelector { NSString *methodName = NSStringFromSelector(aSelector); NSLog(@"respondsToSelector: %@", methodName); return [super respondsToSelector:aSelector]; } */ @end Hopefully, you guys can see something obvious that I've missed. Thank you!

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