[R] repeat rows of matrix by number (k) in one colummatrix adding column j with values 1:k
Rasmus Liland
jen@r@@mu@ @end|ng |rom gm@||@com
Thu Apr 2 22:04:47 CEST 2020
On 2020-04-01 15:33 +1100, Jim Lemon wrote:
> Hi Nevil,
> It's a nasty piece of work, but:
Hi! How about this one:
data <- c(rep(1:4, times=3), 2, 1, 3, 2)
dimnames <- list(NULL, c("x", "y", "z", "k"))
ncol <- length(data)/4
M <- matrix(data=data, nrow=ncol, ncol=ncol, dimnames=dimnames)
FUN <- function(x) {
out <- matrix(rep(x[1:3], times=x[4]),
byrow=TRUE, nrow=x[4])
return(cbind(out, x[4]))
}
newM <- do.call(rbind, apply(X=M, MARGIN=1, FUN=FUN))
dimnames(newM) <- list(NULL, c("x", "y", "z", "k"))
newM <- cbind(newM, "j"=sequence(M[,"k"]))
newM
Regards,
Rasmus
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