Hi Manuel, Of course it is not a bug. The spherical Bessel function j_0 = sin(x)/x, so you can check this value by direct calculation, which indeed gives the value that you get.
Best wishes, Alex On Tue, May 3, 2016 at 1:46 AM Manuel Segovia <[email protected]> wrote: > Hello > please check the following could this be a “bug”? > > gsl @2.1 (math, science) > Mac OSX “el Capitan” 10.11.4 > i am using Clang and compile instructions are: > clang -L/opt/local/lib -lgsl main.o -o bessel > > # include <stdio.h> > # include <gsl/gsl_sf_bessel.h> > int main (void) > { > double x = 5.0; > double y = gsl_sf_bessel_j0 (x); > printf ("JO(%g) = %.18e\n", x , y); > return(0); > } > the result i get is JO(5) = -1.917848549326277019e-01 > instead of -1.775967713143382920e-01 this is the result indicated in the > gsl manual 2.1 example program > Thanks > >
