Re: [R] Matrix oriented computing

From: Patrick Burns <pburns_at_pburns.seanet.com>
Date: Fri 26 Aug 2005 - 23:21:34 EST

I believe that the following is what you want:

x <- c(0.005, 0.010, 0.025, 0.05, 0.1, 0.5, 0.9, 0.95, 0.975, 0.99, 0.995) dof <- 1:100
ans <- outer(x, dof, qchisq)
dimnames(ans) <- list(x, dof)

Note that 'df' is not a very auspicious name for an object since it is the name of a function.

Patrick Burns
patrick@burns-stat.com
+44 (0)20 8525 0696
http://www.burns-stat.com
(home of S Poetry and "A Guide for the Unwilling S User")

Sigbert Klinke wrote:

>Hi,
>
>I want to compute the quantiles of Chi^2 distributions with different
>degrees of freedom like
>
>x<-cbind(0.005, 0.010, 0.025, 0.05, 0.1, 0.5, 0.9, 0.95, 0.975, 0.99, 0.995)
>df<-rbind(1:100)
>m<-qchisq(x,df)
>
>and hoped to get back a length(df) times length(x) matrix with the
>quantiles. Since this does not work, I use
>
>x<-c(0.005, 0.010, 0.025, 0.05, 0.1, 0.5, 0.9, 0.95, 0.975, 0.99, 0.995)
>df<-c(1:100)
>m<-qchisq(x,df[1])
>for (i in 2:length(df)) {
> m<-rbind(m,qchisq(x,df[i]))
>}
>dim(m)<-c(length(df),length(x))
>
>Is there a way to avoid the for loop ?
>
>Thanks Sigbert
>
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>
>
>
>



R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Aug 27 03:47:10 2005

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