[Help-gsl] 2D Fourier transform

[Goo Creations]

Hi all,

I know this question was answered sometime last year, but I can't figure out
how to use 2D FFT.

What I currently have

*//4x4 array. Every i is real, every i+1 is imag
** //This array is 16, because 4x4, and *2, because we have to store real
and imag*

*double *a = new double[16*2];

gsl_fft_complex_radix2_forward(a, 1, 16);
*

Now as far as I know, to solve 2D FFT, I must first do a column-based FFT
and then a row-based FFT (according to last years post).
How exactly will I do this, is there another function in GSL?

Thanks for any help!!