Re: [Help-gsl] Gsl-1.8 compiled and running under MSYS-1.10+second order derivative

[Brian Gough]

Rene Girard wrote:

> double g1(double, double *);
>
> I would like to bring to your attention that when I
> compile that simple example and
> I set the pointer to the function from we want to have
> the derivative with the following
> statement:
>  
>   f.function = &g1; (like in the example in Chap. 27)
>
> I get the following warning:
>
> "warning: assignment from incompatible pointer type"
>
> to remove the warning I had to cast the pointer as
> follow:
>
>  f.function = (double (*) ()) &g1;

Hello,
Thanks for your email.  I think your warning can be avoided without a 
cast by using the prototype double g1(double, void *) which matches the 
definition in GSL.  Otherwise, the appropriate cast would be (double 
(*)(double, void *)). See the header file gsl_math.h for the definition 
of the gsl_function type.

--
best regards,

Brian Gough
(GSL Maintainer)

Network Theory Ltd,
Publishing the GSL Manual - http://www.network-theory.co.uk/gsl/manual/