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Re: CORRELATE where is the problem? [message #65471]

Sun, 08 March 2009 12:39

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

xiao writes:

> Hi~ everyone. I have a simple question here. I have two arrays and I
> calculated the correlation between them. The result is 0.49. But when
> I use the equation to calculate the correlation. The result is 0.99.
> And I can see from the plot that they are actually highly correlated.
> Why is that? THX
>
> openr,1,'data.txt'
> data=fltarr(2,1227)
> readf,1,data
>
> temp=data(1,*)
> oo=data(0,*)
> ;print,temp(0)
>
> temp=reform(temp)
> oo=reform(oo)
>
> corr=CORRELATE(oo,temp)
> print,corr
> rr=LINFIT(temp,oo)
> print,rr
> plot,psym=2,temp,oo

Which equation are you talking about? My guess is
you have constructed the equation incorrectly.

Cheers,

David

--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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[Message index]

		Re: CORRELATE where is the problem? By: David Fanning on Sun, 08 March 2009 12:39
		Re: CORRELATE where is the problem? By: xiao zhang on Sun, 08 March 2009 13:35

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