The R Project SVN R

\name{formatC}
\title{Flexible Formatting}
\usage{
formatC(x, digits=NULL, width=max(0,digits)+1,
        format=NULL, flag="", mode=NULL)
}
\alias{formatC}
\arguments{
\item{x}{an atomic numerical or character object,
typically a vector of real numbers.}
\item{digits}{the desired number of digits after
the decimal point. Default: 2 for integer,
4 for real numbers.  \code{digits} < 0 uses
the default for C, namely  6 digits.}
\item{width}{the total field width; \code{width < 0}
means left justify the number in this field
(equivalent to \code{flag ="-"}).
It is possible that the result will be longer than this,
but that should only happen in reasonable cases.}
\item{format}{equal to \code{"d"}  (for integers),
\code{"f"}, \code{"e"}, \code{"E"}, \code{"g"}, \code{"G"}
(for `real'), or \code{"s"} (for strings).
\code{"f"} gives numbers in the usual ``xxx.xxx'' format;
\code{"e"} and \code{"E"} give ``n.ddde<nn>'' or ``n.dddE<nn>''
(scientific  format); \code{"g"} and \code{"G"} put \code{x[i]}
into scientific format only if it saves space to do so.}
\item{flag}{format modifier as in Kernighan and Ritchie, 2nd ed., p.243.
\code{"0"}  pads leading zeros; \code{"-"} does left adjustment,
others are \code{"+"}, \code{" "}, and \code{"#"}.}
\item{mode}{\code{"real"},  \code{"integer"} or \code{"character"}.
Default: Automatic.}
}
\value{
A character object of same size and attributes as \code{x}.
Unlike \code{format}, each number is individually formatted.
A for loop over each element of \code{x}, calling \code{sprintf(\dots)}
is done in the C function \code{str_signif}.

For  character  arguments,  simple (left or right) padding with
white space is done.
}
\note{
This function was originally written by Bill Dunlap
and later much improved by Martin Maechler.
It was adapted for R by Friedrich Leisch.
}
\seealso{
\code{\link{format}}.
}
\examples{
xx  <- pi*10^(-5:4)
options(digits=4)   # only for format
cbind(format(xx), formatC(xx))
cbind(formatC(xx, wid=9, flag='-'))
cbind(formatC(xx, dig=5,  wid=8, format="f", flag='0'))

formatC(c("a", "Abc", "no way"), wid = -7)#  -  <=> flag = '-'
}