# Which FFT algorithm does Fourier[…] use?

Does anyone know which Fast Fourier Transform algorithm Mathematica uses to compute a Discrete Fourier Transform using Fourier[...], and is there any option to change the algorithm to that of another type?

E.g. Cooley-Tukey (most common), or Bruun's Algorithm?

• Just to check, are you trying to change the algorithm or the scaling? The latter is done using the option FourierParameters. – Hugh Feb 25 at 18:39
• I don't know the algorithm used, sorry. A good question to ask. MathWorld discusses possible algorithms but does not state which is used in Mathematica. – Hugh Feb 25 at 18:56
• Relevant (but as vague as we are used it by WRI ;)) reference.wolfram.com/language/tutorial/… The MKL is mentioned there with no word although I actually know that it is used at least somewhere... – Henrik Schumacher Feb 25 at 19:21
• "FourierOptions" /. SystemOptions[] will give some information though it will not indicate alternatives. – Daniel Lichtblau Feb 25 at 22:04
• You can also use SystemOptions["FourierOptions"] directly, as an alternative to @Daniel's suggestion. On a different note, I had (apparently mistakenly) thought Mathematica was now using FFTW. – J. M. is away Feb 26 at 8:26