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C:/temp/src/j2k/Beta/Math/Vector/NotDone/Gauss/test_gaussj.cpp File Reference

#include <time.h>
#include <stdio.h>
#include <stdlib.h>

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Functions
void	main ()

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Function Documentation

void main (  void    )

Definition at line 5 of file test_gaussj.cpp. { int i, j, k, n = 2000, n2 = n * n, t0, t = 0; double *A = (double *) malloc(n2 * sizeof(double)); double *a[4096], b[4096], x[4096], e, ee; a[0] = A; for (i = 1; i < n; i++) a[i] = a[i-1] + n; srand(clock()); for (i = 0; i < n2; i++) A[i] = 0.0; for (i = 0; i < n; i++) a[i][i] = 1.0; for (k = n; k < 6000; k++) { do i = rand() * n / 32768, j = rand() * n / 32768; while (i <= j || a[i][j]); a[i][j] = (1 + rand()) / 32768.0; } for (k = 0; k < n2; k++) { i = rand() * n / 32768; j = rand() * n / 32768; e = a[i][j]; a[i][j] = a[j][i]; a[j][i] = e; } for (k = i = 0; i < n; i++) for (j = 0; j < n; j++) if (a[i][j]) k++; printf("k = %d\n", k); for (i = 0; i < n; i++) x[i] = rand() / 32767.0; for (i = 0; i < n; i++) for (b[i] = j = 0; j < n; j++) b[i] += a[i][j]*x[j]; t0 = clock(); a[n] = b; if (!gaussj(a, n, 1, 1e-7)) return; t += clock() - t0; for (e = i = 0; i < n; i++) if ((ee = fabs(x[i] - b[i])) > e) e = ee; printf("Error = %e, Time = %d\n", e, t); free(A); }

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