changeset 17091:641c47e8bcae

doc: expand on FFT size argument to fftfilt * fftfilt.m: Explain how the FFT size argument is used and adjusted internally to meet certain constraints.
author Mike Miller <mtmiller@ieee.org>
date Fri, 26 Jul 2013 01:44:06 -0400
parents 1d544ac39369
children 498b9f62199a
files scripts/signal/fftfilt.m
diffstat 1 files changed, 5 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/scripts/signal/fftfilt.m	Fri Jul 26 06:53:17 2013 +0200
+++ b/scripts/signal/fftfilt.m	Fri Jul 26 01:44:06 2013 -0400
@@ -23,7 +23,11 @@
 ## @var{b} using the FFT.
 ##
 ## Given the optional third argument, @var{n}, @code{fftfilt} uses the
-## overlap-add method to filter @var{x} with @var{b} using an N-point FFT.
+## overlap-add method to filter @var{x} with @var{b} using an @var{n}-point
+## FFT.  The FFT size must be an even power of 2 and must be greater than
+## or equal to the length of @var{b}.  If the specified @var{n} does not
+## meet these criteria, it is automatically adjusted to the nearest value
+## that does.
 ##
 ## If @var{x} is a matrix, filter each column of the matrix.
 ## @seealso{filter, filter2}