Hello in R how could I write a function which takes as an input a number at which aline should be entered into an existing object
matrix(rnorm(9),ncol=3,nrow=5)
x<-c(1,7,8)
Each vector should now be entered into the matrix into the matrix at row 3 (so it should be the new co row 3 . The other rows would just be a pushed so the old row 3 is row 4 then
Here's a function I wrote for that a while back. I've been using it.
#Christopher Barry, 28/01/2015
insertRows <- function(DF, mtx, row){
if(is.vector(mtx)){
mtx <- matrix(mtx, 1, length(mtx), byrow=T)
}
nrow0 <- nrow(DF)
nrows <- nrow(mtx)
ncols <- ncol(DF) #should be same as for mtx
if(is.matrix(DF)){DF <- rbind(DF, matrix(0, nrows, ncols))}
if(nrow0 >= row){
DF[seq(row+nrows,nrow0+nrows),] <- DF[seq(row,nrow0),]
DF[row:(row+nrows-1),] <- mtx
}else{
DF[seq(nrow0+1,nrow0+nrows),] <- mtx
}
return (DF)
}
Edited to work for matrices and data frames.
One way of doing this can be :
aa<- matrix(rnorm(9),ncol=3,nrow=5)
x<-c(1,7,8)
rbind(aa[1:2,],x,aa[3:5,])
A similar solution ot this, actually: R: Insert a vector as a row in data.frame
