https://github.com/cran/pracma
Tip revision: 708a2ad382a163d1eef5af0665e3ae2aad200ced authored by HwB on 21 March 2013, 00:00:00 UTC
version 1.4.5
version 1.4.5
Tip revision: 708a2ad
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)}.
}
\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 }