| numeric {base} | R Documentation |
Numeric Vectors
Description
numeric creates a real vector of the specified length. The
elements of the vector are all equal to 0.
as.numeric attempts to coerce its argument to numeric type
(either integer or real).
is.numeric returns TRUE if its argument is of type real
or type integer and FALSE otherwise.
Usage
numeric(length = 0)
as.numeric(x, ...)
is.numeric(x)
Arguments
length |
desired length. |
x |
object to be coerced or tested. |
... |
further arguments passed to or from other methods. |
Note
R has no single precision data type. All real numbers are
stored in double precision format. While as.numeric is a
generic function, user methods must be written for as.double,
which it calls
as.numeric for factors yields the codes underlying the factor
levels, not the numeric representation of the labels.
Examples
as.numeric(c("-.1"," 2.7 ","B")) # (-0.1, 2.7, NA) + warning
as.numeric(factor(5:10))