Hi everyone
I am not very familiar with nr but I had some problems with the fftw library recently therefore I thought I implement the fft of nr and compare it to the fftw library output... the function I suppose I have to use is

rlft3.c

however the manual totally confused me (page 519 and following) on how I actually have to provide the input... I would like to perform a 3D complex to real transform.
The first problem I have is that data[], which is one of the input arrays needs the values store with index 1 to nn1 and 1 to nn2 and 1 to nn3. Since C is indexing arrays from 0 to n-1 I don't understand that at all???
I would really appreciate if anybody could give me a quick example on how I have to provide the input

I have a function x[kx][ky][kz] with real and complex values... and I have to distribute this function between data[] and speq[]...
thanks for any help
and best regards
fl

Hi
I think I was wrong, the program I have to use for a complex-to-real transform is fourn.c... Am I right that the input in this case is alternating between real and complex

x[0] = real1
x[1] = im1
x[2] = real2
x[3] = im2
...

best regards
florian