Double Precision Vectors

Description

Create, coerce to or test for a double-precision vector.

Usage

double(length = 0)
as.double(x, ...)
is.double(x)

single(length = 0)
as.single(x, ...)

Arguments

Value

double creates a double precision vector of the specified length. The elements of the vector are all equal to 0.
as.double attempts to coerce its argument to be of double type: like as.vector it strips attributes including names. Character strings containing either a decimal representation or a heaxadecimal representation (starting with 0x or 0X) can be converted.
is.double returns TRUE or FALSE depending on whether its argument is of double type or not. It is generic: you can write methods to handle specific classes of objects, see InternalMethods.

Note

R has no single precision data type. All real numbers are stored in double precision format. The functions as.single and single are identical to as.double and double except they set the attribute Csingle that is used in the .C and .Fortran interface, and they are intended only to be used in that context.

References

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

See Also

integer, numeric.

Examples

is.double(1)
all(double(3) == 0)