st: Re: RE: summing up matrix elements

["R.E. De Hoyos" <redeho@hotmail.com>]

Dear Jamie and Nick,

Both your solutions work fine, thanks a lot. 
I though there was a non-mata matrix function similar to mata's -sum(C)-

Best regards,
Rafa


----- Original Message ----- 
From: "Nick Cox" <n.j.cox@durham.ac.uk>
To: <statalist@hsphsun2.harvard.edu>
Sent: Tuesday, November 08, 2005 3:28 PM
Subject: st: RE: summing up matrix elements



> . mata : sum_r = (sum(C) - trace(C)) / 2
>
> Nick 
> n.j.cox@durham.ac.uk 
> R.E. De Hoyos
>  
> > > Is there a way to to get a scalar containing the sum of the 
> > > off-diagonal 
> > > elements of a pre-defined matrix?
> > > 
> > > For instance, define matrix C  as a correlation matrix. I 
> > > want to know what 
> > > is the sum of correlations between the various elements in C. 
> > > Therefore I 
> > > need the sum of all elements in C minus the sum of the 
> > > diagonal elements 
> > > (-trace(C)-) and finally divide it by 2 (I am assuming matric C is 
> > > symetric).
>
>
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