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
trapz.Rd
\name{trapz}
\alias{trapz}
\title{Trapezoidal Integration}
\description{
Compute the area of a function with values \code{y} at the points
\code{x}.
}
\usage{
trapz(x, y)
}
\arguments{
\item{x}{x-coordinates of points on the x-axis}
\item{y}{y-coordinates of function values}
}
\details{
The points \code{(x, 0)} and \code{(x, y)} are taken as vertices of a
polygon and the area is computed using \code{polyarea}.
This approach matches exactly the approximation for integrating the
function using the trapezoidal rule with basepoints \code{x}.
}
\value{
Approximated integral of the function from \code{min(x)} to \code{max(x)}.
}
\author{
hwb \email{hwborchers@googlemail.com}
}
\seealso{
\code{\link{polyarea}}
}
\examples{
# Calculate the area under the sine curve from 0 to pi:
x <- seq(0, pi, len=101)
y <- sin(x)
trapz(x, y) #=> 1.999836
}
\keyword{ math }