try this:

V <- var(matrix(rnorm(100*3), 100, 3))
w <- c(0.5, 0.3, 0.2)

V * (w %o% w)


I hope it helps.

Best,
Dimitris

----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
     http://www.student.kuleuven.be/~m0390867/dimitris.htm


Quoting Dan Stanger <[EMAIL PROTECTED]>:

Hello All,

I have a covariance matrix, generated by read.table, and cov:

co<-cov(read.table("c:/r.x"))

             X            Y            Z

X 0.0012517684 0.0002765438 0.0007887114

Y 0.0002765438 0.0002570286 0.0002117336

Z 0.0007887114 0.0002117336 0.0009168750



And a weight vector generated by

w<- read.table("c:/r.weights")

          X         Y         Z

1 0.5818416 0.2158531 0.2023053



I want to compute the product of the matrix and vectors termwise to
generate a 3x3 matrix, where m[i,j]=w[i]*co[i,j]*w[j].

0.000423773 7.47216E-08 4.41255E-08

7.47216E-08 1.96566E-11 4.29229E-11

4.41255E-08 4.29229E-11 4.11045E-11



Is this possible without writing explicit loops?

Thank you,

Dan Stanger

Eaton Vance Management
200 State Street
Boston, MA 02109
617 598 8261




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