https://github.com/cran/pracma
Tip revision: 71455748623ef69836470c75c5f9384f6e872d45 authored by HwB on 28 June 2011, 00:00:00 UTC
version 0.6-3
version 0.6-3
Tip revision: 7145574
ifactor.Rd
\name{ifactor}
\alias{ifactor}
\title{Prime Factors}
\description{
Returns a vector containing the prime ifactor of \code{n}.
}
\usage{
ifactor(n)
}
\arguments{
\item{n}{nonnegative integer}
}
\details{
Computes the prime factors of \code{n} in ascending order,
each one as often as its multiplicity requires, such that
\code{n == prod(ifactor(n))}.
The corresponding Matlab function is called `factor', but because
factors have a special meaning in R and the factor() funtion in R
could not (or should not) be shadowed, the number theoretic function
has been renamed here.
}
\value{
vector containing the prime factors of \code{n}.
}
\author{
hwb \email{hwborchers@googlemail.com}
}
\seealso{
\code{\link{isprime}, \link{primes}}
}
\examples{
\dontrun{
ifactor(1002001) # 7 7 11 11 13 13
ifactor(65537) # is prime
# Euler's calculation
ifactor(2^32 + 1) # 641 6700417}
}
\keyword{ math }