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Re: ListCorrelate on lists with different sampling rates

  • To: mathgroup at smc.vnet.net
  • Subject: [mg87399] Re: ListCorrelate on lists with different sampling rates
  • From: "jwmerrill at gmail.com" <jwmerrill at gmail.com>
  • Date: Wed, 9 Apr 2008 05:57:50 -0400 (EDT)
  • References: <ftfell$bv7$1@smc.vnet.net>

On Apr 8, 5:42 am, Curtis Osterhoudt <c... at lanl.gov> wrote:
> Hi, all,
>
>    I've been beating my head against this problem (only half an hour at a
> time, though, which may well be my mistake) for a little while now, and was
> wondering if people had some input.
>
>    I'm basically looking at the cross-correlation (or sliding dot-product) of
> two sampled (discrete) signals---one a drive signal and one a received
> signal---to pick out various features. I'm doing this using Mathematica's
> ListCorrelate, which is working admirably, and I can easily pick out echoes
> and so on.
>
>    However, my question concerns what to do when the sampled signals have
> different time scales. As I understand it, the ListCorrelate function really
> only works (for this application) when the input lists are one-dimensional.
> If the sampling rates are different, I can go ahead and (for example)
> resample the higher-sample-rate signal (via interpolation) to the same rate
> as the lower-sample-rate signal, and then perform the ListCorrelation. It
> seems to me, though, that I'm sort of throwing away some information that I
> don't need to in the resampling procedure.
>
>    Is that the recommended procedure, or is there something more clever I can
> do?
>
> ==========================================================
> Curtis Osterhoudt
> cfo at remove_this.lanl.and_this.gov
> PGP Key ID: 0x4DCA2A10
> Please avoid sending me Word or PowerPoint attachments
> Seehttp://www.gnu.org/philosophy/no-word-attachments.html
> ==========================================================

Interpolate the data sampled at the lower rate up to the higher rate?


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