crossprod                package:base                R Documentation

Matrix Crossproduct

Description:

     Given matrices `x' and `y' as arguments, `crossprod' returns their
     matrix cross-product. This is formally equivalent to, but faster
     than, the call `t(x) %*% y'.

Usage:

     crossprod(x, y=x)

Arguments:

    x, y: matrices.

See Also:

     `%*%' and outer product `%o%'.

Examples:

     (z <- crossprod(1:4))    # = sum(1 + 2^2 + 3^2 + 4^2)
     drop(z)                  # scalar

