gsl for complex number

[Aleramo]

I have to do a program using complex matrix and vector, but i have some
problem to find the function to do it. It means i have problems to
extend the function of libraries gsl_matrix.h e gsl_vector.h. I hope
someone can send some of the programs made about it so i can use it as
example.
Now i am tring to extend: gsl_vector_mul (). I used
gsl_vector_complex_mul() but i receive:

prodottovettori.c:13: warning: implicit declaration of function
`gsl_vector_complex_mul'
/tmp/ccUES3mp.o(.text+0x98): In function `main':
: undefined reference to `gsl_vector_complex_mul'
collect2: ld returned 1 exit status

Bye bye Marco.