Fastest way for multiplying a matrix to a vector

Question

I have a matrix mat and a vector v. I would like to multiply first column of matrix matby first element of vector v and m

Answer 1

sweep seems to run a bit faster on my machine

sweep(mat, 2, v, FUN = "*")

Some benchmarks:

> microbenchmark(mat %*% diag(v),sweep(mat, 2, v, FUN = "*"))

Unit: milliseconds
  expr       min        lq   median        uq      max neval
   %*% 214.66700 226.95551 231.2366 255.78493 349.1911   100
 sweep  42.42987  44.72254  62.9990  70.87403 127.2869   100