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Help with the F-test. mpftest.pro in particular. [message #53297]

Fri, 06 April 2007 08:55

cgguido
Messages: 195
Registered: August 2005

Senior Member

Hi all,

I am trying to figure out how the F-test works.

I created two fake datasets with 1e6 elements and a variance of 4

n = 1e6
s = 4
i1 = randomn(sss, n)*s
i2 = randomn(sss, n)*s

I then calculate the f value as the ration of the largest variance to
the smallest (the two sets have the same number of degrees of freedom,
n)

var = [variance(i1), variance(i2)]
vv = max(var, min=v)
f = vv/v

Then I print the probability that the variances are similar due to
pure chance (should be close to zero because the variances are *set*
to be th same)

print, mpftest(f, n, n)
--> 0.47958397

I must be doing something very wrong :-(

Can somebody help please?

Thanks,
Gianguido

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[Message index]

		Help with the F-test. mpftest.pro in particular. By: cgguido on Fri, 06 April 2007 08:55
		Re: Help with the F-test. mpftest.pro in particular. By: cgguido on Fri, 06 April 2007 11:57
		Re: Help with the F-test. mpftest.pro in particular. By: news.verizon.net on Fri, 06 April 2007 11:49
		Re: Help with the F-test. mpftest.pro in particular. By: cgguido on Wed, 18 April 2007 14:49

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