isTRUE
Test for the Value TRUE
Description
Test for a logical object of length one with the value TRUE.
Usage
isTRUE(x)
Arguments
| x |
The element, object, string, evaluation, or any other type to test.
|
Details
isTRUE is handy for testing the results of functions like
all.equal() and getOption(), which can return TRUE
on success and character strings or NULL on failure.
This function differs slightly from the R implementation of
isTRUE, which is identical(TRUE, x), and thus
returns FALSE for isTRUE(c(one=1)==1).
Value
returns TRUE if x is a logical vector of length one
whose value is TRUE. Otherwise returns FALSE.
Attributes of x, such as names or dimensions, are ignored.
See Also
Examples
isTRUE(all.equal(sqrt(14), sqrt(2)*sqrt(7))) &&
isTRUE(all.equal(1:2,1:3)) # FALSE
# FALSE if this option not set or FALSE
isTRUE(getOption("unusualOption"))
options(unusualOption = TRUE)
isTRUE(getOption("unusualOption")) # TRUE
isTRUE(c(Value=TRUE)) # FALSE in S engines