| logical {base} | R Documentation |
Logical Vectors
Description
Create or test for objects of type "logical", and the basic
logical “constants”.
Usage
TRUE
FALSE
T; F
logical(length = 0)
as.logical(x, ...)
is.logical(x)
Arguments
length |
desired length. |
x |
object to be coerced or tested. |
... |
further arguments passed to or from other methods. |
Details
TRUE and FALSE are part of the R language, where
T and F are global variables set to these.
All four are logical(1) vectors.
is.logical is generic: you can write methods to handle
specific classes of objects, see InternalMethods.
Value
logical creates a logical vector of the specified length.
Each element of the vector is equal to FALSE.
as.logical attempts to coerce its argument to be of logical
type. For factors, this uses the levels
(labels). Like as.vector it strips attributes including
names.
is.logical returns TRUE or FALSE depending on
whether its argument is of logical type or not.
References
Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth \& Brooks/Cole.