Logical Operators

Description

These operators act on logical vectors.

Usage

! x
x & y
x && y
x | y
x || y
xor(x, y)

Details

! indicates logical negation (NOT).

& and && indicate logical AND and | and || 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.

xor indicates elementwise exclusive OR.

See Also

TRUE or logical.

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"