From rtautenh at ipb-halle.de  Thu May 22 17:05:14 2008
From: rtautenh at ipb-halle.de (rtautenh at ipb-halle.de)
Date: Thu, 22 May 2008 17:05:14 +0200 (CEST)
Subject: [Rd] PR#11477
Message-ID: <20080522150514.DC0712834154@mail.pubhealth.ku.dk>

So maybe convolve(x,y) should take care if  x or y is of prime size ?

Or users could at least be warned that this implementation of "Fast
Convolution" is not able to handle x
of prime size in acceptable time.

Anyway, I don't understand why R does not make use of a fast&free
algorithm like the FFTW implementation,
which is able to handle  x  of prime sizes in acceptable time.
"Sizes with small prime factors are best, but FFTW uses O(N log N)
algorithms even for prime sizes."

Ralf.



[Rd] PR#11477
rtautenh at ipb-halle.de