Hey,
I need a subroutine of Fortran90 about "Fast Fourier Transform of a Step-function in 3-dimonsional." I read the related subroutines in Numerical Recipes Book, but I couldn't match it for a 3D step function. Whould you please let me to have access to a subroutine for the mentioned goal?
why don't you use fftw [1] ? It has a fortran 77 api, but i think that it can be called in a fortran 90 program.
regards Vincent Torri [1] http://www.fftw.org/
