R.filesets (version 2.15.1)

TabularTextFile: The TabularTextFile class

Description

Package: R.filesets
Class TabularTextFile

Object
~~|
~~+--FullNameInterface
~~~~~~~|
~~~~~~~+--GenericDataFile
~~~~~~~~~~~~|
~~~~~~~~~~~~+--ColumnNamesInterface
~~~~~~~~~~~~~~~~~|
~~~~~~~~~~~~~~~~~+--GenericTabularFile
~~~~~~~~~~~~~~~~~~~~~~|
~~~~~~~~~~~~~~~~~~~~~~+--TabularTextFile

Directly known subclasses:

public abstract static class TabularTextFile
extends GenericTabularFile

A TabularTextFile is an object referring to a tabular text file on a file system containing data in a tabular format. Methods for reading all or a subset of the tabular data exist.

Usage

TabularTextFile(..., sep=c("\t", ","), quote="\"", fill=FALSE, skip=0L, columnNames=NA,
  commentChar="#", .verify=TRUE, verbose=FALSE)

Arguments

...

Arguments passed to GenericTabularFile.

sep

A character specifying the symbol used to separate the cell entries. If more than one symbol is specified, it will try to select the correct one by peeking into the file.

quote

A character specifying the quote symbol used, if any.

fill

As in read.table.

skip

As in read.table.

columnNames

A logical or a character vector. If TRUE, then column names are inferred from the file. If a character vector, then the column names are given by this argument.

commentChar

A single character specifying which symbol should be used for comments, cf. read.table.

.verify, verbose

(Internal only) If TRUE, the file is verified while the object is instantiated by the constructor. The verbose argument is passed to the verifier function.

Fields and Methods

Methods:

	getHeader	-
	nbrOfLines	-
	nbrOfRows	-
	readDataFrame	-
	readLines	-

Methods inherited from GenericTabularFile:
[, as.character, dim, extractMatrix, head, nbrOfColumns, nbrOfRows, readColumns, readDataFrame, tail, writeColumnsToFiles

Methods inherited from ColumnNamesInterface:
appendColumnNamesTranslator, appendColumnNamesTranslatorByNULL, appendColumnNamesTranslatorBycharacter, appendColumnNamesTranslatorByfunction, appendColumnNamesTranslatorBylist, clearColumnNamesTranslator, clearListOfColumnNamesTranslators, getColumnNames, getColumnNamesTranslator, getDefaultColumnNames, getListOfColumnNamesTranslators, nbrOfColumns, setColumnNames, setColumnNamesTranslator, setListOfColumnNamesTranslators, updateColumnNames

Methods inherited from GenericDataFile:
as.character, clone, compareChecksum, copyTo, equals, fromFile, getAttribute, getAttributes, getChecksum, getChecksumFile, getCreatedOn, getDefaultFullName, getExtension, getExtensionPattern, getFileSize, getFileType, getFilename, getFilenameExtension, getLastAccessedOn, getLastModifiedOn, getOutputExtension, getPath, getPathname, gunzip, gzip, hasBeenModified, is.na, isFile, isGzipped, linkTo, readChecksum, renameTo, renameToUpperCaseExt, setAttribute, setAttributes, setAttributesBy, setAttributesByTags, setExtensionPattern, testAttributes, validate, validateChecksum, writeChecksum

Methods inherited from FullNameInterface:
appendFullNameTranslator, appendFullNameTranslatorByNULL, appendFullNameTranslatorByTabularTextFile, appendFullNameTranslatorByTabularTextFileSet, appendFullNameTranslatorBycharacter, appendFullNameTranslatorBydata.frame, appendFullNameTranslatorByfunction, appendFullNameTranslatorBylist, clearFullNameTranslator, clearListOfFullNameTranslators, getDefaultFullName, getFullName, getFullNameTranslator, getListOfFullNameTranslators, getName, getTags, hasTag, hasTags, resetFullName, setFullName, setFullNameTranslator, setListOfFullNameTranslators, setName, setTags, updateFullName

Methods inherited from Object:
$, $<-, [[, [[<-, as.character, attach, attachLocally, clearCache, clearLookupCache, clone, detach, equals, extend, finalize, getEnvironment, getFieldModifier, getFieldModifiers, getFields, getInstantiationTime, getStaticInstance, hasField, hashCode, ll, load, names, objectSize, print, save

Author

Henrik Bengtsson

See Also

An object of this class is typically part of an TabularTextFileSet.

Examples

path <- system.file("exData/dataSetA,original", package="R.filesets")

db <- TabularTextFile("fileA,20100112.dat", path=path)
print(db)

# Read all data
data <- readDataFrame(db)
print(data)

# Read columns 'x', 'y', and 'char'
data <- readDataFrame(db, colClasses=c("(x|y)"="integer", "char"="character"))
print(data)

# Translate column names on the fly
db <- setColumnNamesTranslator(db, function(names, ...) toupper(names))
data <- readDataFrame(db, colClasses=c("(X|Y)"="integer", "CHAR"="character"))
print(data)