readTable

0th

Percentile

Reads a file in table format

Usage
## S3 method for class 'default}(file, colClasses=NULL, isPatterns=FALSE, defColClass=NA, header=FALSE, skip=0, nrows=-1, rows=NULL, col.names=NULL, check.names=FALSE, path=NULL, ..., stripQuotes=TRUE, method=c("readLines", "intervals"), verbose=FALSE)':
readTableundefined

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

  WARNING: This method is very much in an alpha stage.
  Expect it to change.

  This method is an extension to the default read.table()
  function in R.  It is possible to specify a column name to column class
  map such that the column classes are automatically assigned from the
  column header in the file.

  In addition, it is possible to read any subset of rows.
  The method is optimized such that only columns and rows that are of
  interest are parsed and read into R's memory.  This minimizes memory
  usage at the same time as it speeds up the reading.

 file{A connection or a filename.  If a filename, the path
      specified by path is added to the front of the
      filename.  Unopened files are opened and closed at the end.}
   colClasses{Either a named or an unnamed character vector.
      If unnamed, it specified the column classes just as used by
      read.table().
      If it is a named vector, names(colClasses) are used to match
      the column names read (this requires that header=TRUE) and
      the column classes are set to the corresponding values.
   }
   isPatterns{If TRUE, the matching of names(colClasses) to
      the read column names is done by regular expressions matching.}
   defColClass{If the column class map specified by a named
      colClasses argument does not match some of the read column
      names, the column class is by default set to this class. The
      default is to read the columns in an "as is" way.}
   header{If TRUE, column names are read from the file.}
   skip{The number of lines (commented or non-commented) to skip
      before trying to read the header or alternatively the data table.}
   nrows{The number of rows to read of the data table.
      Ignored if rows is specified.}
   rows{An row index vector specifying which rows of the table
      to read, e.g. row one is the row following the header.
      Non-existing rows are ignored.  Note that rows are returned in
      the same order they are requested and duplicated rows are also
      returned.}
   col.names{Same as in read.table().}
   check.names{Same as in read.table(), but default value
      is FALSE here.}
   path{If file is a filename, this path is added to it,
     otherwise ignored.}
   ...{Arguments passed to read.table() used internally.}
   stripQuotes{If TRUE, quotes are stripped from values before
     being parse.
     This argument is only effective when method=="readLines".
   }
   method{If "readLines", (readLines()) is used
     internally to first only read rows of interest, which is then
     passed to read.table().
     If "intervals", contigous intervals are first identified in
     the rows of interest.  These intervals are the read one by one
     using read.table().
     The latter methods is faster and especially more memory efficient
     if the intervals are not too many, where as the former is prefered
     if many "scattered" rows are to be read.}
   verbose{A logical or a Verbose object.}

 Returns a data.frame.

 [object Object]

 readTableIndex().
  read.table().


IO
Aliases
  • readTable.default
  • readTable
Documentation reproduced from package R.utils, version 0.7.9, License: LGPL version 2.1 or newer (the releases)

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