Re: about QAWF integration -- Fourier integrals

[Brian Gough <bjg at network-theory dot co dot uk>]

xie qiong writes:
 > double myfunc(double x, void *params)
 > {
 >         double a = *(double *)params;

Hi,
In this function add,

       if (x == 0.0) return 0.0;

to avoid computing 0/0.  The cutoff of 1e-30 is problematic with the
current implementation based on the original QUADPACK code.  This
could be improved in a future version of GSL.

 >         
 > 	return exp(- log(x) * log(x)/(2.0 * a * a)) /
 > (sqrt(2.0 * PI) * a * x);
 > }

regards
Brian