| % File src/library/stats/man/ksmooth.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2014 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{ksmooth} |
| \alias{ksmooth} |
| \title{Kernel Regression Smoother} |
| \description{ |
| The Nadaraya--Watson kernel regression estimate. |
| } |
| \usage{ |
| ksmooth(x, y, kernel = c("box", "normal"), bandwidth = 0.5, |
| range.x = range(x), |
| n.points = max(100L, length(x)), x.points) |
| } |
| \arguments{ |
| \item{x}{input x values. Long vectors are supported.} |
| \item{y}{input y values. Long vectors are supported.} |
| \item{kernel}{the kernel to be used. Can be abbreviated.} |
| \item{bandwidth}{the bandwidth. The kernels are scaled so that their |
| quartiles (viewed as probability densities) are at |
| \eqn{\pm}{+/-} \code{0.25*bandwidth}.} |
| \item{range.x}{the range of points to be covered in the output.} |
| \item{n.points}{the number of points at which to evaluate the fit.} |
| \item{x.points}{points at which to evaluate the smoothed fit. If |
| missing, \code{n.points} are chosen uniformly to cover |
| \code{range.x}. Long vectors are supported.} |
| } |
| \value{ |
| A list with components |
| \item{x}{values at which the smoothed fit is evaluated. Guaranteed to |
| be in increasing order.} |
| \item{y}{fitted values corresponding to \code{x}.} |
| } |
| \note{ |
| This function was implemented for compatibility with S, |
| although it is nowhere near as slow as the S function. Better kernel |
| smoothers are available in other packages such as \CRANpkg{KernSmooth}. |
| } |
| \examples{ |
| require(graphics) |
| |
| with(cars, { |
| plot(speed, dist) |
| lines(ksmooth(speed, dist, "normal", bandwidth = 2), col = 2) |
| lines(ksmooth(speed, dist, "normal", bandwidth = 5), col = 3) |
| }) |
| } |
| \keyword{smooth} |