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Re: Correlation function and data

• To: mathgroup at smc.vnet.net
• Subject: [mg24748] Re: Correlation function and data
• From: "Deborah Leddon " <Dleddon at students.cas.unt.edu>
• Date: Wed, 9 Aug 2000 02:31:56 -0400 (EDT)
• Organization: University of North Texas
• Sender: owner-wri-mathgroup at wolfram.com

Hello,
 I am trying to construct an autocorrelation function that can be 
applied to a data set as follows;

n=Length[data];
c[y_]:= Sum[(data[[i]] - Mean[data] )* ( data[[i+y]] - Mean[data])/
		Variance[data], {i,1,n - y}];
corrfunction = Array[c, {n - 1}];

ListPlot[corrfunction, PlotJoined->True]

Problem is , this routine works well for data sets up to a length of 
300 points, but gets unusually long for larger data sets , say 
around 1000-3000 points in length. I've tried  "Map" (using 
anonymous function rules), Table-Evaluate, etc..

Anyone got any ideas? I would much appreciate them!

Regards,
Deb L.

• Follow-Ups:
  • Re: Re: Correlation function and data
    • From: Daniel Lichtblau <danl@wolfram.com>