multidimenstional minimization without df.

[Toan T Nguyen]

Hi,

I'd like to locate the minimum point of a function f(x_i) of n variables 
x_i. It's very non trivial to calculate the df/dx_i. Can I use conjugate 
gradian method without this df(x_i) information ?

This page in the manual 
http://www.gnu.org/software/gsl/manual/html_node/Multimin-Algorithms.html

doesn't list gsl_multimin_fminimizer_conjugate_fr as a type of 
minimizer. It has
        gsl_multimin_fdfminimizer_conjugate_fr
but no
        gsl_multimin_fminimizer_conjugate_fr

Any help would be appreciated.

Thanks,
Toan