integer {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 \pm 2 \times 10^9: doubles 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)

---