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