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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