TITLE(Logic @@ Logical Operators)
USAGE(
x & y
x && y
x | y
x || y
! x
)
ALIAS(&)
ALIAS(&&)
ALIAS(|)
ALIAS(||)
ALIAS(!)
ALIAS(Logic)
DESCRIPTION(
These operators act on logical vectors.
LANG(&) and LANG(&&) indicate logical AND and LANG(|) and LANG(||)
indicate logical OR.
The shorter form performs elementwise comparisons in
much the same way as arithmetic operators.
The longer form evaluates left to right examining only the
first element of each vector.
Evaluation proceeds only until the result is determined.
The longer form is appropriate for programming control-flow.
PARA
LANG(!) indicates logical negation (NOT).
)
EXAMPLES(
y <- 1 +  (x <- rpois(50, lambda=1.5)/4 - 1)
x[(x > 0) & (x < 1)]    # all x values between 0 and 1
if(any(x==0) || any(y==0)) "zero encountered"
)
