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type.convert {utils}

Type Conversion on Character Variables
Package: 
utils
Version: 
R 3.0.2

Description

Convert a character vector to logical, integer, numeric, complex or factor as appropriate.

Usage

type.convert(x, na.strings = "NA", as.is = FALSE, dec = ".")

Arguments

x
a character vector.
na.strings
a vector of strings which are to be interpreted as NA values. Blank fields are also considered to be missing values in logical, integer, numeric or complex vectors.
as.is
logical. See ‘Details’.
dec
the character to be assumed for decimal points.

Details

This is principally a helper function for read.table. Given a character vector, it attempts to convert it to logical, integer, numeric or complex, and failing that converts it to factor unless as.is = TRUE. The first type that can accept all the non-missing values is chosen (numeric and complex return values will represented approximately, of course).

Vectors which are entirely missing values are converted to logical, since NA is primarily logical.

Vectors containing just F, T, FALSE, TRUE and values from na.strings are converted to logical. Vectors containing optional whitespace followed by decimal constants representable as R integers or values from na.strings are converted to integer. Other vectors containing optional whitespace followed by other decimal or hexadecimal constants (see NumericConstants), or NaN, Inf or infinity (ignoring case) or values from na.strings are converted to numeric.

Since this is a helper function, the caller should always pass an appropriate value of as.is.

Values

A vector of the selected class, or a factor.

See Also

read.table

Documentation reproduced from R 3.0.2. License: GPL-2.