Multiplies two matrices, if they are conformable.
If one argument is a vector, it will be coerced to either a row or
column matrix to make the two arguments conformable.
If both are vectors it will return the inner product.
Usage
a %*% b
Arguments
a, b
numeric or complex matrices or vectors.
Value
The matrix product. Use drop to get rid of dimensions
which have only one level.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988)
The New S Language.
Wadsworth & Brooks/Cole.
x <- 1:4(z <- x %*% x) # scalar ("inner") product (1 x 1 matrix)drop(z) # as scalar
y <- diag(x)
z <- matrix(1:12, ncol = 3, nrow = 4)
y %*% z
y %*% x
x %*% z