double                 package:base                 R Documentation

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:

  length: desired length.

       x: object to be coerced or tested.

     ...: further arguments passed to or from other methods.

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.

     `is.double' returns `TRUE' or `FALSE' depending on whether its
     argument is of double type or not.

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.

See Also:

     `integer'.

Examples:

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

