crossprod {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 = NULL)

Arguments

x, y	matrices: y = NULL is taken to be the same matrix as x.

See Also

%*% and outer product %o%.

Examples

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

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