integer                 package:base                 R Documentation

Integer Vectors

Description:

     Creates or tests for objects of type '"integer"'.

Usage:

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

Arguments:

  length: desired length.

       x: object to be coerced or tested.

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

Details:

     Integer vectors exist so that data can be passed to C or Fortran
     code which expects them, and so that small integer data can be
     represented exactly and compactly.

     Note that on almost all implementations of R the range of
     representable integers is restricted to about +/-2*10^9: 'double's
     can hold much larger integers exactly.

Value:

     'integer' creates a integer vector of the specified length. Each
     element of the vector is equal to '0'.

     'as.integer' attempts to coerce its argument to be of integer
     type. The answer will be 'NA' unless the coercion succeeds. Real
     values larger in modulus than the largest integer are coerced to
     'NA' (unlike S which gives the most extreme integer of the same
     sign). Non-integral numeric values are truncated towards zero
     (i.e., 'as.integer(x)' equals 'trunc(x)' there), and imaginary
     parts of complex numbers are discarded (with a warning). Character
     strings containing either a decimal representation or a
     hexadecimal representation (starting with '0x' or '0X') can be
     converted, as well as any allowed by the platform for real
     numbers. Like 'as.vector' it strips attributes including names.
     (To ensure that an object is of integer type without stripping
     attributes, use 'storage.mode'.)

     'is.integer' returns 'TRUE' or 'FALSE' depending on whether its
     argument is of integer type or not, unless it is a factor when it
     returns 'FALSE'.

References:

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

See Also:

     'numeric', 'storage.mode'.

     'round' (and 'ceiling' and 'floor' on that help page) to convert
     to integral values.

Examples:

       ## as.integer() truncates:
       x <- pi * c(-1:1,10)
       as.integer(x)

