[R] Summation in R

Dina Said dinasaid at gmail.com
Tue Oct 3 11:50:39 CEST 2006


   Thanks Pikal for your reply
   I want element wise summation. If t is a vector of 5, v is a matrix of
   5*5  then  I want the answer to be a matrix of 5*5 by multiplying each
   element in t (t_j) by  each vector in v (v_j).
   Dina
   Petr Pikal wrote:

Hi

you shall probably to be more specific

tj<-rnorm(5)
vj<-matrix(25,5,5)
sum(tj*vj)
[1] 149.2977

gives you an answer but maybe not the answer you want.

HTH
Petr


On 3 Oct 2006 at 8:58, Dina Said wrote:

Date sent:              Tue, 03 Oct 2006 08:58:15 +0200
From:                   Dina Said [1]<dinasaid at gmail.com>
To:                     [2]r-help at stat.math.ethz.ch
Subject:                [R] Summation in R



Hello!

Maybe this is a trivial question as I'm still a new baby in R but I
wish that u will help me.

I want to calculate the following

U= sum (t_j*v_j)

where t_j is a vector
and v_j is the matrix

Thanks
Dina

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Petr Pikal
[6]petr.pikal at precheza.cz

References

   1. mailto:dinasaid at gmail.com
   2. mailto:r-help at stat.math.ethz.ch
   3. mailto:R-help at stat.math.ethz.ch
   4. https://stat.ethz.ch/mailman/listinfo/r-help
   5. http://www.R-project.org/posting-guide.html
   6. mailto:petr.pikal at precheza.cz


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