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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Do not modify this file since it was automatically generated from:
%
% readTableIndex.R
%
% by the Rdoc compiler part of the R.oo package.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\name{readTableIndex}
\alias{readTableIndex.default}
\alias{readTableIndex}
\title{Reads a single column from file in table format}
\usage{
\method{readTableIndex}{default}(..., indexColumn=1, colClass="character", verbose=FALSE)
}
\description{
Reads a single column from file in table format, which can then be used as a index-to-row (look-up) map
for fast access to a subset of rows using \code{\link{readTable}}().
}
\arguments{
\item{indexColumn}{An single \code{\link[base]{integer}} of the index column.}
\item{colClass}{A single \code{\link[base]{character}} specifying the class of the
index column.}
\item{...}{Arguments passed to \code{\link{readTable}}() used internally.}
\item{verbose}{A \code{\link[base]{logical}} or a \code{\link{Verbose}} object.}
}
\value{
Returns a \code{\link[base]{vector}}.
}
\examples{\dontrun{
# File containing data table to be access many times
filename <- "somefile.txt"
# Create a look-up index
index <- readTableIndex(filename)
# Keys of interest
keys <- c("foo", "bar", "wah")
# Read only those keys and do it fast
df <- readTable(filename, rows=match(keys, index))
}}
\author{Henrik Bengtsson}
\seealso{
\code{\link{readTable}}().
}
\keyword{IO}
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