matmult {base} | R Documentation |
Multiplies two matrices, if they are conformable. If one argument is a vector, it will be coerced to a either a row or column matrix to make the two arguments conformable. If both are vectors it will return the inner product.
a%*%b
The matrix product. Use drop
to get rid of
matrix
, Arithmetic
, diag
.
x <- 1:4 x%*%x # scalar ("inner") product (1 x 1 matrix) drop(.Last.value)# as scalar y <- diag(x) z <- matrix(1:12,ncol=3,nrow=4) y%*%z y%*%x x%*%z