[R] multiplying a matrix by a vector
dimitri.liakhovitski at gmail.com
Thu Nov 3 22:05:12 CET 2016
I have a matrix x and a vector y:
x <- matrix(1:6, ncol = 2)
y <- c(2,3)
I need to multiply the first column of x by 2 (y) and the second
column of x by 3 (y).
Of course, I could do this - but it's column by column:
x[,1] <- x[,1] * y
x[,2] <- x[,2] * y
Or I could repeat each element of y and multiply two matrices - that's better:
y <- rep.row(y, nrow(x))
x * y
However, maybe there is a more elegant r-like way of doing it?
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