Re: [R] multiplication question

From: Henrique Dallazuanna <wwwhsd_at_gmail.com>
Date: Wed, 02 Jul 2008 18:03:42 -0300

Try something about like this:

v1 %o% v2 - diag(v1*v2)

On Wed, Jul 2, 2008 at 1:30 PM, Murali Menon <feanor0_at_hotmail.com> wrote:

>
> folks,
>
> is there a clever way to compute the sum of the product of two vectors such
> that the common indices are not multiplied together?
>
> i.e. if i have vectors X, Y, how can i compute
>
> Sum (X[i] * Y[j])
> i != j
>
> where i != j
>
> also, what if i wanted
>
> Sum (X[i] * Y[j] * R[i, j])
> i != j
>
> where R is a matrix?
>
> thanks,
>
> murali
>
>
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-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

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Received on Wed 02 Jul 2008 - 21:06:10 GMT

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