type.convert(x, na.strings = "NA", as.is = FALSE, dec = ".", numerals = c("allow.loss", "warn.loss", "no.loss"))
NA
values. Blank fields are also considered to be
missing values in logical, integer, numeric or complex vectors.x
has more digits than can be stored in a double
.
Can be abbreviated. Possible values are
numerals = "allow.loss"
, default:
numerals = "warn.loss"
:warning
about accuracy loss is signalled and the conversion happens as
with numerals = "allow.loss"
.
numerals = "no.loss"
:x
is not
converted to a number, but to a factor
or left as
character, depending on as.is
. This has been the only
behavior of R version 3.1.0.
as.is = FALSE
) a factor.
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. 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. Where converting inputs to numeric or complex would result
in loss of accuracy they can optionally be 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
.
read.table