Re: gsl_function

[Marek Nečada]

Hi Patrick,

you can't return a complex with gsl_function.

Integrate the real and imaginary parts separately.

Best regards,
Marek Nečada



Patrick Dupre kirjoitti 16.6.2020 klo 11.29:
> Hello,
> 
> I need to return a complex with a gsl_function.
> How can I do?
> 
> Here is an example
> 
> #include <math.h>
> #include <stdio.h>
> #include <complex.h>
> #include <gsl/gsl_integration.h>
> 
> double complex tt (double complex z) {
>   double complex y = 0 ;
>   for (unsigned short int i = 0 ; i < 5 ; i++) {
>     y += z ;
>     }
>   return y ;
>   }
> 
> main () {
>   gsl_function fcn ;
>   double complex y0 = 1 + I * 0.5 ;
>   fcn.function = &tt ;
>   double complex z = tt (y0) ;
>   double complex zz = (double complex) fcn.function (y0, fcn.params) ;
>   printf ("%g %g, %g %g\n", z, zz) ;
>   }
> 
> Result (zz is not correct)
> 5 2.5, 5 0
> 
> Some ideas?
> 
> Thanks
> 
> ===========================================================================
>  Patrick DUPRÉ                                 | | email: pdupre@gmx.com
>  Laboratoire interdisciplinaire Carnot de Bourgogne
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