The R Project SVN R

Rev

Rev 61433 | Rev 68948 | Go to most recent revision | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed

Rev 61433 Rev 61810
Line 1... Line 1...
1 
% File src/library/base/man/double.Rd
 1 
% File src/library/base/man/double.Rd
2 
% Part of the R package, http://www.R-project.org
 2 
% Part of the R package, http://www.R-project.org
3 
% Copyright 1995-2011 R Core Team
 3 
% Copyright 1995-2013 R Core Team
4 
% Distributed under GPL 2 or later
 4 
% Distributed under GPL 2 or later
5 
 
 5 
 
6 
\name{double}
 6 
\name{double}
7 
\title{Double-Precision Vectors}
 7 
\title{Double-Precision Vectors}
8 
\alias{double}
 8 
\alias{double}
Line 30... Line 30...
30 
  \item{\dots}{further arguments passed to or from other methods.}
 30 
  \item{\dots}{further arguments passed to or from other methods.}
31 
}
 31 
}
32 
\details{
 32 
\details{
33 
  \code{double} creates a double-precision vector of the specified
 33 
  \code{double} creates a double-precision vector of the specified
34 
  length.  The elements of the vector are all equal to \code{0}.
 34 
  length.  The elements of the vector are all equal to \code{0}.
35 
  It is identical to \code{\link{numeric}} (and \code{real}).
 35 
  It is identical to \code{\link{numeric}}.
36 
 
 36 
 
37 
  \code{as.double} is a generic function.  It is identical to
 37 
  \code{as.double} is a generic function.  It is identical to
38 
  \code{as.numeric} (and \code{as.real}).  Methods should return an
 38 
  \code{as.numeric}.  Methods should return an object of base type
39 
  object of base type \code{"double"}.
 39 
  \code{"double"}.
40 
 
 40 
 
41 
  \code{is.double} is a test of double \link{type}.
 41 
  \code{is.double} is a test of double \link{type}.
42 
 
 42 
 
43 
  \emph{\R has no single precision data type.  All real numbers are
 43 
  \emph{\R has no single precision data type.  All real numbers are
44 
    stored in double precision format}.  The functions \code{as.single}
 44 
    stored in double precision format}.  The functions \code{as.single}
Line 86... Line 86...
86 
 
 86 
 
87 
  In IEEE 754-2008/IEC60559:2011 this is called \sQuote{binary64} format.
 87 
  In IEEE 754-2008/IEC60559:2011 this is called \sQuote{binary64} format.
88 
}
 88 
}
89 
%% keep next the same in double.Rd & numeric.Rd
 89 
%% keep next the same in double.Rd & numeric.Rd
90 
\section{Note on names}{
 90 
\section{Note on names}{
91 
  It is a historical anomaly that \R has three names for its
 91 
  It is a historical anomaly that \R has two names for its
92 
  floating-point vectors, \code{\link{double}}, \code{\link{numeric}}
 92 
  floating-point vectors, \code{\link{double}} and \code{\link{numeric}}
93 
  and \code{\link{real}}.
 93 
  (and formerly had \code{real}).
94 
 
 94 
 
95 
  \code{double} is the name of the \link{type}.
 95 
  \code{double} is the name of the \link{type}.
96 
  \code{numeric} is the name of the \link{mode} and also of the implicit
 96 
  \code{numeric} is the name of the \link{mode} and also of the implicit
97 
  \link{class}.  As an S4 formal class, use \code{"numeric"}.
 97 
  \link{class}.  As an S4 formal class, use \code{"numeric"}.
98 
 
 98 
 
99 
  \code{real} is deprecated and should not be used in new code.
 - 
 
100 
 
 - 
 
101 
  The potential confusion is that \R has used \emph{\link{mode}}
 99 
  The potential confusion is that \R has used \emph{\link{mode}}
102 
  \code{"numeric"} to mean \sQuote{double or integer}, which conflicts
 100 
  \code{"numeric"} to mean \sQuote{double or integer}, which conflicts
103 
  with the S4 usage.  Thus \code{is.numeric} tests the mode, not the
 101 
  with the S4 usage.  Thus \code{is.numeric} tests the mode, not the
104 
  class, but \code{as.numeric} (which is identical to \code{as.double})
 102 
  class, but \code{as.numeric} (which is identical to \code{as.double})
105 
  coerces to the class.
 103 
  coerces to the class.