Re: [R] to replace the for loop
Hi,
May be this helps:
set.seed(42)
T <- matrix(sample(1:20,20,replace=TRUE),ncol=5)
TEMP <- T
T1 <- T
for(i in 1: nrow(TEMP)){
for(j in 1: nrow(TEMP)){if (i <= j) T[i, j] <- 0 }}
indx <- expand.grid(rep(list(1:nrow(TEMP)),2))[,2:1]
T1[as.matrix(indx[indx[,1] <= indx[,2],])] <- 0
#or
library(gtools)
indx <- permutations(nrow(TEMP),2,1:nrow(TEMP),repeats=TRUE)
T1[indx[indx[,1] <= indx[,2],]] <- 0
identical(T,T1)
#[1] TRUE
A.K.
Hello
I would like to replace the for loop this below
T <- as.matrix(T)
for(i in 1: nrow(TEMP)){
for(j in 1: nrow(TEMP)){if (i <= j) T[i, j] <- 0 }}
I don't find the function in the doc.
Thanks in advance for your help.
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Re: [R] to replace the for loop
On 14-12-2013, at 08:01, Arnaud Michel wrote:
> Hello
>
> I would like to replace the for loop this below
>
> T <- as.matrix(T)
> for(i in 1: nrow(TEMP)){
> for(j in 1: nrow(TEMP)){if (i <= j) T[i, j] <- 0 }}
>
Your code is mangled.
We don’t know what T is.
You refer to TEMP in the for loop but you most likely meant T.
Shouldn’t the second nrow in your for loop be ncol?
> I don't find the function in the doc.
Search with ??uppertri and you’ll find lower.tri in base with sufficient
description to have a look at that entry.
Depending on what packages you have, you may find more.
> Thanks in advance for your help.
>
T[col(T)>=row(T)] <- 0
T[upper.tri(T,diag=TRUE) ] <- 0
Berend
> --
> Michel ARNAUD
> Chargé de mission auprès du DRH
> DGDRD-Drh - TA 174/04
> Av Agropolis 34398 Montpellier cedex 5
> tel : 04.67.61.75.38
> fax : 04.67.61.57.87
> port: 06.47.43.55.31
>
> __
> R-help@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.
__
R-help@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.
[R] to replace the for loop
Hello
I would like to replace the for loop this below
T <- as.matrix(T)
for(i in 1: nrow(TEMP)){
for(j in 1: nrow(TEMP)){if (i <= j) T[i, j] <- 0 }}
I don't find the function in the doc.
Thanks in advance for your help.
--
Michel ARNAUD
Chargé de mission auprès du DRH
DGDRD-Drh - TA 174/04
Av Agropolis 34398 Montpellier cedex 5
tel : 04.67.61.75.38
fax : 04.67.61.57.87
port: 06.47.43.55.31
__
R-help@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.
