https://github.com/cran/pracma
Tip revision: 63e8a52ae6668e736720c89691352d6dc3bc9eb1 authored by HwB on 17 January 2012, 00:00:00 UTC
version 0.9.6
version 0.9.6
Tip revision: 63e8a52
mrank.Rd
\name{mrank}
\alias{mrank}
\title{
Matrix Rank
}
\description{
Provides an estimate of the rank of a matrix \code{M}.
}
\usage{
mrank(M)
}
\arguments{
\item{M}{Numeric matrix; vectors will be considered as column vectors.}
}
\details{
Provides an estimate of the number of linearly independent rows or columns
of a matrix \code{M}. Compares an approach using QR-decomposition with one
counting singular values larger than a certain tolerance (Matlab).
}
\value{
Matrix rank as integer between \code{0} and \code{min(ncol(M), nrow(M))}.
}
\references{
Trefethen, L. N., and D. Bau III. (1997). Numerical Linear Algebra. SIAM,
Philadelphia.
}
\author{
HwB email: <hwborchers@googlemail.com>
}
\note{
The corresponding function in Matlab is called \code{rank}, but that term
has a different meaning in R.
}
\seealso{
\code{\link{nullspace}}
}
\examples{
mrank(magic(10)) #=> 7
mrank(magic(100)) #=> 3 (!)
mrank(hilb(8)) #=> 8 , but qr(hilb(8))$rank says, rank is 7.
# Warning message:
# In mrank(hilb(8)) : Rank calculation may be problematic.
}
\keyword{ array }