Re: n-point FFT

[tandp(at)mindone.net (Mike)]

In article <onzoit8fai.fsf@cow.physics.wisc.edu>,
craigmnet@cow.physics.wisc.edu wrote:

> Jean Marc Delvit <delvit@onecert.fr> writes:
> > 
> > I wants to know how to do a n-point FFT with IDL
> > the same of FFT(X,n) in matlab (if the length of X is less than n, X is
> > padded with trailing zeros to length n)
> 
> ... and if you read the documentation, you will find that the IDL
> routine FFT will work on an array of any size.  It's very easy to
> do any needed zero-padding yourself (ie, fft([x, fltarr(nzeros)]) ).
> 
> Craig

It should also be noted that IDL 5.4 implements a mixed-radix FFT. Time
series of length equal to a power of 2 are no longer a prerequisite for
performance. This eases the need for zero-padding and improves the
accuracy of time series that can conform to the radices (radiches?) used.

Mike