3 #include <gsl/gsl_integration.h>
5 double f (double x, void * params) {
6 double alpha = *(double *) params;
7 double f = log(alpha*x) / sqrt(x);
14 gsl_integration_workspace * w
15 = gsl_integration_workspace_alloc (1000);
18 double expected = -4.0;
25 gsl_integration_qags (&F, 0, 1, 0, 1e-7, 1000,
28 printf ("result = % .18f\n", result);
29 printf ("exact result = % .18f\n", expected);
30 printf ("estimated error = % .18f\n", error);
31 printf ("actual error = % .18f\n", result - expected);
32 printf ("intervals = %d\n", w->size);
34 gsl_integration_workspace_free (w);