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Topic: alternative to conv command
Replies: 7   Last Post: Apr 29, 2011 10:18 PM

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Balachander Narasimhan

Posts: 39
Registered: 2/4/08
Re: alternative to conv command
Posted: Apr 29, 2011 10:18 PM
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Hi,

thanks for your interest in my problem. You should try the complex case. In my computer, the real case took 8 secs and the complex case of the same size took 79 seconds. But when I use the fft method, the complex case took only about 4 seconds. this is huge savings!!

ImageAnalyst <imageanalyst@mailinator.com> wrote in message <0b2c972e-1705-47f7-a138-2a26dcca2a91@n10g2000yqf.googlegroups.com>...
> So you're filtering a signal that's "2048e3" (that's 2048000) long
> with a kernel that's 2048 long? That's a big kernel. But it's still
> fast. Look:
>
> clc;
> data = rand(1,2048000);
> tic
> smoothedData = conv(data, ones(2049,1)/3);
> toc
>
> Elapsed time is 1.541351 seconds.
>
> I made the kernel an odd number of elements (as is normally done) just
> to make sure it's symmetric.
>
>
> So did you try the Fourier method like I suggested?




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