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  1. #include <iostream>
  2. #include <cmath>
  3. #include <cstdio>
  4.  
  5. using namespace std;
  6.  
  7. // Definicja funkcji
  8. double f(double x)
  9. {
  10.     return 0.25 * x * x - 2;
  11. }
  12.  
  13. int main()
  14. {
  15.     FILE* gnuplot = popen("gnuplot -persistent", "w");
  16.  
  17.     if (!gnuplot)
  18.     {
  19.         cout << "Blad uruchomienia gnuplot." << endl;
  20.         return 1;
  21.     }
  22.  
  23.     // Ustawienia wykresu
  24.     fprintf(gnuplot, "set title 'Wykres funkcji f(x) = 1/4 x^2 - 2'\n");
  25.     fprintf(gnuplot, "set xlabel 'x'\n");
  26.     fprintf(gnuplot, "set ylabel 'f(x)'\n");
  27.     fprintf(gnuplot, "set grid\n");
  28.     fprintf(gnuplot, "set zeroaxis\n");
  29.     fprintf(gnuplot, "set xrange [1:5]\n");
  30.  
  31.     // Rysowanie wykresu
  32.     fprintf(gnuplot, "plot '-' with lines lw 2 title 'f(x)'\n");
  33.  
  34.     for (double x = 1.0; x <= 5.0; x += 0.01)
  35.     {
  36.         fprintf(gnuplot, "%f %f\n", x, f(x));
  37.     }
  38.  
  39.     fprintf(gnuplot, "e\n");
  40.     fclose(gnuplot);
  41.  
  42.     return 0;
  43. }
  44.  
Success #stdin #stdout #stderr 0.01s 5332KB
comments (?)
stdin 
Standard input is empty
stdout 
Standard output is empty
stderr 
sh: 1: gnuplot: not found
https://ideone.com/99Me4S
language:
C++ (gcc 8.3)
created:
3 days ago
visibility:
public

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