From: Vincent Goulet <vincent.goulet_at_act.ulaval.ca>

Date: Tue, 06 May 2008 15:36:23 -0400

Date: Tue, 06 May 2008 15:36:23 -0400

Le mar. 06 mai à 14:23, Alberto Monteiro a écrit :

>> 3) Bill Venables offered this about a week ago in this list:

*>> --------------
**>> This is probably as good a way as any way for this kind of problem.
**>> First define a binary operator:
**>>
**>>> "%^%" <- function(x, n)
**>> with(eigen(x), vectors %*% (values^n * t(vectors)))
**>>
**> This example only works for _diagonalizable_ matrices. It
**> crashes, for example, in cases like:
**>
**> m <- rbind(c(1,1,0), c(0,1,1), c(0,0,1))
**> m %^% 2
**> m %*% m
*

Then the %^% operator defined in package expm [1] will work for any kind of (square) matrix. The actual work is done in C, so it is pretty fast.

[1] On R-Forge: http://r-forge.r-project.org/projects/expm/

--- Vincent Goulet, Associate Professor École d'actuariat Université Laval, Québec Vincent.Goulet@act.ulaval.ca http://vgoulet.act.ulaval.ca ______________________________________________ R-help_at_r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.Received on Tue 06 May 2008 - 19:43:33 GMT

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