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POofstream error using << operator
 

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  1. POofstream error using << operator
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    <p>I got error when I use ofstream outputting an double array to a txt file. Here is the code:</p> <pre><code>static void OutpuResults(std::string fileName, double * yCal, int nPtCal) { std::string value; double * yCal_local = yCal; std::ofstream outfile; outfile.open(fileName.c_str()); for (int i = 0; i &lt; nPtCal; i++) { outfile&lt;&lt;yCal_local[i]&lt;&lt;std::endl; } delete[] yCal_local; outfile.close(); } </code></pre> <p>Error occurs at <code>outfile&lt;&lt;yCal_local[i]&lt;&lt;std::endl;</code> where i = 0, and <code>yCal_local[i]</code> is 0.000000 as a double. Makes no sesne to me.</p> <p>Here is the definition of fileName:</p> <pre><code>std::string fileName = "d:\\inter.txt"; </code></pre> <p>and here is the definition of yCal:</p> <pre><code>int nPtCal = 256; double * yCal = new double[nPtCal]; </code></pre> <p>I am wondering where I did wrong? Any suggestion is appreciate it.</p> <p>Edit: It does not have a problem when compling it, but error occurs when it is running. Here is the error message:</p> <pre><code>Unhandled exception at 0x75f5812f in ppppp.exe: Microsoft C++ exception: std::bad_alloc at memory location 0x0028f754.. </code></pre> <p>And here is the code showing up when the program returns from error:</p> <pre><code>void __cdecl _unlock ( int locknum ) { /* * leave the critical section. */ LeaveCriticalSection( _locktable[locknum].lock ); } </code></pre> <p>Edit:</p> <p>Here is all the code:</p> <pre><code>#include "pppp.h" #include &lt;iostream&gt; #include &lt;fstream&gt; #include &lt;string&gt; #include &lt;vector&gt; static void show_usage(std::string name) { std::cerr &lt;&lt; "To use ZoomCal:\n " &lt;&lt; "ZoomCal.exe inputfile -options\n" &lt;&lt; "options:\n" &lt;&lt; " -l: linear\n" &lt;&lt; " -c: cubic"&lt;&lt; std::endl; } static void LoadData(std::string fileName, double* y) { std::string value; double * y_local = y; char *cstr = new char[fileName.length() + 1]; std::strcpy(cstr, fileName.c_str()); std::ifstream infile; infile.open(cstr); if (!infile.is_open()) { std::cerr&lt;&lt;"File loading failed. Double check if file exists in the same folder as ZoomCal.exe"&lt;&lt;std::endl; exit(1); } int count = 0; int i = 0; int col = 10; while ( infile.good() ) { getline ( infile, value, ',' ); // read a string until next comma: http://www.cplusplus.com/reference/string/getline/ if (count % col == 0) { if (count != 0) { *y_local = std::atof(value.c_str()); y_local++; } } count++; } //delete [] cstr; //delete y_local; infile.close(); } static void OutpuResults(std::string fileName, double * yCal, int nPtCal) { std::string value; //double * yCal_local = yCal; std::ofstream outfile; outfile.open(fileName.c_str()); for (int i = 0; i &lt; nPtCal; i++) { outfile&lt;&lt;yCal[i]&lt;&lt;std::endl; } // delete[] yCal_local; outfile.close(); } double * LinInterp(double * y, int nPt, int nPtCal) { double * yCal = new double[nPtCal]; double * tmp = new double[nPtCal-5]; int interval = 10; double * pPiece = new double[interval]; double f2, f1, m, b; int x2, x1; std::memset(yCal, 0, sizeof(double)*nPtCal); tmp += 6; for (int i = 0; i &lt; (nPt - 1); i ++) { *pPiece = *y; f2 = *(y + 1); f1 = *y; x2 = (i + 1) * interval; x1 = i * interval; m = (f2 - f1)/(x2 - x1); b = f2 - m * x2; for (int k = 1; k &lt; interval; k++) { pPiece[k] = m * ((i * interval) + k) + b; } std::memcpy(tmp + (i * interval), pPiece, sizeof(double)*interval); y++; } std::memcpy(yCal + 6, tmp, sizeof(double)*250); return yCal; } double * CubInterp(double * y, int nPt, int nPtCal) { double * yCal = new double[nPtCal]; std::memset(yCal, 0, sizeof(double)*nPtCal); return yCal; } int main(int argc, char* argv[]) { if (argc &lt; 3) { show_usage(argv[0]); return 1; } std::vector &lt;std::string&gt; sources; std::string destination; for (int i = 1; i &lt; argc; ++i) { std::string arg = argv[i]; if ((arg == "-h") || (arg == "--help")) { show_usage(argv[0]); return 0; } else if ((arg == "-d") || (arg == "--destination")) { if (i + 1 &lt; argc) { // Make sure we aren't at the end of argv! destination = argv[i++]; // Increment 'i' so we don't get the argument as the next argv[i]. } else { // Uh-oh, there was no argument to the destination option. std::cerr &lt;&lt; "--destination option requires one argument." &lt;&lt; std::endl; return 1; } } else { sources.push_back(argv[i]); } } int nPt = 26; double * y = new double[nPt]; LoadData(sources[0], y); int nPtCal = 256; double * yCal = new double[nPtCal]; yCal = LinInterp(y, nPt, nPtCal); std::string fileName = "D:\\inter.txt"; OutpuResults(fileName, yCal, nPtCal); getchar(); return 1; } </code></pre>
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    1. USNick Tsui
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    1. COis it compiler error? can you show us the error?
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      1. USidoo
    2. COSorry, let me edit a little more.
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      1. USNick Tsui
    3. COYou have more problems than that: To start with you say you want to write to a text file, but you open the file in binary mode. The most serious problem might be the `delete` at the end of the function though, especially if you want to use the array you pass to the function after the call.
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      1. USSome programmer dude
 

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