Fortran Fast Fourier Transform Similiar to MATLAB's FFT

[jowens1988]

Hello All,

I'm new to the forums here.

I am writing a program that is analyzing some pressure data, and I need to take the Fourier transform of a matrix. I am translating already written MATLAB code into Fortran.

After hours of searching online, I am having trouble finding an algorithm that works like MATLAB's FFT, that is, returns the same type of output. Does anybody know of a Fortran subroutine that is written which can do this?

I can provide you that code/data that I am using, if you need it!

Thanks ahead for any help!

 

[xwb]

FFT is FFT - the behaviour is always the same. What sort of input/output are you looking for? Is it something fancy like

http://cimss.ssec.wisc.edu/~paulv/fft/fft_comparison.html

Also is it a F77 or F90 version you're looking for?

 

[jowens1988]

xwb: Thanks for the website.

I have some large vector full of real numbers, and I want to return the FFT of them, which is a vector of complex numbers.

My inputs are in the time domain; my outputs should be the frequency domain Power Spectrum.

I'm not sure if this information narrows it down anymore for you, or not.

I'm going to play with the programs on the website you gave me, and hopefully I can get something out of that. The nice thing is, I have data which I can check against, so I know pretty fast if it's doing what I need it to.

Thanks again!

 

[jowens1988]

*Edit: I'm doing the coding in Fortran 95, by the way. Sorry, I forgot to add that earlier!