学步园

#define GSL_DLL

#include <stdio.h>
#include <gsl/gsl_sf_bessel.h>

#pragma comment(lib, "libgsl_dll_d.lib")
#pragma comment(lib, "libgslcblas_dll_d.lib")

int
main (void)
{
  double x = 5.0;
  double expected = -0.17759677131433830434739701;
  
  double y = gsl_sf_bessel_J0 (x);

  printf ("J0(5.0) = %.18f\n", y);
  printf ("exact   = %.18f\n", expected);
  return 0;
}