R: The TabularTextFile class

TabularTextFile {R.filesets} | R Documentation

## 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 refering 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(s)

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)

[Package R.filesets version 2.11.0 Index]