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Re: 2D FFT Slow. Any ideas? [message #37246 is a reply to message #37234]

Fri, 05 December 2003 13:05

R.G. Stockwell
Messages: 363
Registered: July 1999

Senior Member

"Brian" <brian.huether@NOdlrSPAM.de> wrote in message
news:a298a85e9af4e70d51199dcae50c4c81@news.teranews.com...
> I did a little benchmark between IDL and MATLAB. In each case I created a
> random double precision complex array of size 2048 by 2048 and timed how
> long the 2D FFT took. In MATLAB 6.5 it took about 3.5 sec, and in IDL, it
> took about 10 sec. Is there a way to have IDL use MATLAB for the FFT,
> perhaps using activex? Or would the overhead in using activex defeat the
> purpose?
>
> thanks,
>
> brian
>

Hi Brian,
I found some time to take a look at this, and I see the same thing you do.
This is on a 1.13 ghz dell inspiron 8100 laptop running win2000.
Matlab 6.5 did the fft of 2048 by 2048 array of doubles in 0.9 seconds.
IDL 6.0 did it in 4.6 seconds (ram 109 MBs).

Wow, that is surprising. The idl version is quite slow.

For a double complex array IDL takes 8.1 seconds (ram 174 MBs),
matlab takes 1.6 sec (211 mb ram).

Interesting.

-bob

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[Message index]

		Re: 2D FFT Slow. Any ideas? By: Brian on Mon, 08 December 2003 00:02
		Re: 2D FFT Slow. Any ideas? By: R.G. Stockwell on Fri, 05 December 2003 13:05
		Re: 2D FFT Slow. Any ideas? By: K. Bowman on Fri, 05 December 2003 10:32
		Re: 2D FFT Slow. Any ideas? By: R.G. Stockwell on Fri, 05 December 2003 10:04
		Re: 2D FFT Slow. Any ideas? By: Richard French on Mon, 08 December 2003 12:17

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