double annihilation_total(double E)
{
const gsl_integration_glfixed_table *gl_table;
gl_table = gsl_integration_glfixed_table_alloc(pts);
gsl_function F;
F.function = &annihilation;
F.params = (void*) &E;
return gsl_integration_glfixed (&F, 0.0, M_PI, gl_table);
}
static VALUE rb_gsl_integration_glfixed(VALUE obj, VALUE aa, VALUE bb, VALUE tt)
{
gsl_function *f;
double a, b;
gsl_integration_glfixed_table *t;
double res;
if (!rb_obj_is_kind_of(tt, cgsl_integration_glfixed_table)) {
rb_raise(rb_eTypeError, "Wrong arugment type (%s for GSL::Integration::Glfixed_table)",
rb_class2name(CLASS_OF(tt)));
}
Data_Get_Struct(tt, gsl_integration_glfixed_table, t);
a = NUM2DBL(aa);
b = NUM2DBL(bb);
Data_Get_Struct(obj, gsl_function, f);
res = gsl_integration_glfixed(f, a, b, t);
return rb_float_new(res);
}