fft — Fourier Transform
fft calculates the forward Fourier Transform of the argument
matrix. If the argument is a row or column vector, then the transformation
is performed on that vector. However if the argument is not such a vector,
then the transformation is performed on each column in turn.
The result is not scaled.
An optional scalar argument can be used to zero-pad or to truncate
the argument to a certain length.
To perform two dimensional Fourier Transforms, repeated calls to
fft are required, taking the second call in the other direction.
This is shown below.
Subsections