\name{dot}
\alias{dot}
\title{Scalar Product}
\description{
'dot' or 'scalar' product of vectors or pairwise columns of matrices.
}
\usage{
dot(x, y)
}
\arguments{
\item{x}{numeric vector or matrix}
\item{y}{numeric vector or matrix}
}
\details{
Returns the 'dot' or 'scalar' product of vectors or columns of matrices.
Two vectors must be of same length, two matrices must be of
the same size.
If \code{x} and \code{y} are column or row vectors, their dot product
will be computed as if they were simple vectors.
}
\value{
A scalar or vector of length the number of columns of \code{x} and
\code{y}.
}
\seealso{
\code{\link{cross}}
}
\examples{
dot(1:5, 1:5) #=> 55
# Length of space diagonal in 3-dim- cube:
sqrt(dot(c(1,1,1), c(1,1,1))) #=> 1.732051
}
\keyword{ array }