# st: RE: Re: Contrasts [Stata 9]

 From "FEIVESON, ALAN H. (AL) (JSC-SK) (NASA)" To "'statalist@hsphsun2.harvard.edu'" Subject st: RE: Re: Contrasts [Stata 9] Date Wed, 25 May 2005 11:12:37 -0500

```Janet - You need two rows of C because you have a 2 df comparison - e.g. 1
vs 2 and 1 vs 3 (or equivalently 1 vs 2 and 2 vs 3 , etc). So what if you
try

Mat c=(1,-1,0,0,0,0 \ 1,0 -1,0,0,0)

Test(c)

I can't check this since I don't have Stata 9 yet.

Al Feiveson

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Janet Rait
Sent: Wednesday, May 25, 2005 9:37 AM
To: statalist@hsphsun2.harvard.edu
Subject: st: Re: Contrasts [Stata 9]

Can somebody please put me out of my misery. I have a simple oneway anova
with 6 treatments. I can contrast any pair of treatments after anova using
mat c1=(0,1,-1,0,0,0,0) test, test(c1) etc. But what I want to do is just
compare treatments 1, 2 and 3 and for the life of me I cannot get the matrix
in the right form mat c2=(0,1,1,1,-1,-1,-1) seems to comapre 1,2,3 with
4,5,6.
Thanks,
Janet

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