| % File src/library/base/man/Math.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2012 R Core Team |
| % Copyright 2002-2012 The R Foundation |
| % Distributed under GPL 2 or later |
| |
| \name{MathFun} |
| \title{Miscellaneous Mathematical Functions} |
| \usage{ |
| abs(x) |
| sqrt(x) |
| } |
| \alias{abs} |
| \alias{sqrt} |
| \description{ |
| \code{abs(x)} computes the absolute value of x, \code{sqrt(x)} computes the |
| (principal) square root of x, \eqn{\sqrt{x}}.% Details for complex x are below |
| |
| The naming follows the standard for computer languages such as C or Fortran. |
| } |
| \arguments{ |
| \item{x}{a numeric or \code{\link{complex}} vector or array.} |
| } |
| \details{ |
| These are \link{internal generic} \link{primitive} functions: methods |
| can be defined for them individually or via the |
| \code{\link[=S3groupGeneric]{Math}} group generic. For complex |
| arguments (and the default method), \code{z}, \code{abs(z) == |
| \link{Mod}(z)} and \code{sqrt(z) == z^0.5}. |
| |
| \code{abs(x)} returns an \code{\link{integer}} vector when \code{x} is |
| \code{integer} or \code{\link{logical}}. |
| } |
| \section{S4 methods}{ |
| Both are S4 generic and members of the |
| \code{\link[=S4groupGeneric]{Math}} group generic. |
| } |
| \seealso{ |
| \code{\link{Arithmetic}} for simple, \code{\link{log}} for logarithmic, |
| \code{\link{sin}} for trigonometric, and \code{\link{Special}} for |
| special mathematical functions. |
| |
| \sQuote{\link{plotmath}} for the use of \code{sqrt} in plot annotation. |
| } |
| \references{ |
| Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) |
| \emph{The New S Language}. |
| Wadsworth & Brooks/Cole. |
| } |
| \examples{ |
| require(stats) # for spline |
| require(graphics) |
| xx <- -9:9 |
| plot(xx, sqrt(abs(xx)), col = "red") |
| lines(spline(xx, sqrt(abs(xx)), n=101), col = "pink") |
| } |
| \keyword{math} |