R: Read specified columns from a file

read.columns {limma}

R Documentation

Read specified columns from a file

Description

Reads specified columns from a file in table format and creates a data frame from it, with cases corresponding to lines and variables to fields in the file.

Usage

read.columns(file,required.col=NULL,text.to.search="",sep="\t",quote="\"",skip=0,fill=TRUE,blank.lines.skip=TRUE,comment.char="",allowEscapes=FALSE,...)

Arguments

`file`	the name of the file which the data are to be read from.
`required.col`	character vector of names of the required columns
`text.to.search`	character string. If any column names can be found in this string, those columns will also be read.
`sep`	the field separator character
`quote`	character string of characters to be treated as quote marks
`skip`	the number of lines of the data file to skip before beginning to read data.
`fill`	logical: if `TRUE` then in case the rows have unequal length, blank fields are implicitly added.
`blank.lines.skip`	logical: if `TRUE` blank lines in the input are ignored.
`comment.char`	character: a character vector of length one containing a single character or an empty string.
`allowEscapes`	logical. Should C-style escapes such as `\n` be processed or read verbatim (the default)?
`...`	other arguments are passed to `read.table`, excluding the following which are reserved and cannot be set by the user: `header`, `col.names`, `check.names` and `colClasses`.

Details

This function is an interface to read.table in the base package. It uses required.col and text.to.search to set up the colClasses argument of read.table.

Note the following arguments of read.table are used by read.columns and therefore cannot be set by the user: header, col.names, check.names and colClasses.

This function is used by read.maimages.

Value

A data frame (data.frame) containing a representation of the data in the file.

Author(s)

Gordon Smyth