type.convert {utils}  R Documentation 
Convert a character vector to logical, integer, numeric, complex or factor as appropriate.
type.convert(x, na.strings = "NA", as.is = FALSE, dec = ".")
x 
a character vector. 
na.strings 
a vector of strings which are to be interpreted as

as.is 
logical. See ‘Details’. 
dec 
the character to be assumed for decimal points. 
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
nonmissing values is chosen.
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. As from R 3.1.0, where converting inputs to numeric or
complex would result in loss of accuracy they are returned as strings
(for as.is = TRUE
) or factors.
Since this is a helper function, the caller should always pass an
appropriate value of as.is
.
An atomic vector or (for as.is = FALSE
) a factor.