Logic

R Base 3.6.2

These operators act on raw, logical and number-like vectors.

Syntax

! x
x & y
x && y
x | y
x || y
xor(x, y)<p></p><p>isTRUE (x)
isFALSE(x)</p>

Arguments

Parameter	Description
`x, y`	raw, logical or ‘number-like’ vectors (i.e., of types double (class numeric), integer and complex), or objects for which methods have been written.

Return Value

For !, a logical or raw vector(for raw x) of the same length as x: names, dims and dimnames are copied from x, and all other attributes (including class) if no coercion is done. For |, & and xor a logical or raw vector. If involving a zero-length vector the result has length zero. Otherwise, the elements of shorter vectors are recycled as necessary (with a warning when they are recycled only fractionally). The rules for determining the attributes of the result are rather complicated. Most attrib

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 and typically preferred in if clauses. xor indicates elementwise exclusive OR. isTRUE(x) is the same as { is.logical(x) && length(x) == 1 && !is.na(x) && x }; isFALSE() is defined analogously. Consequently, if(isTRUE(cond)) may be preferable to if(cond) because of NAs. In earlier R versions, isTRUE <- function(x) identical(x, TRUE), had the drawback to be false e.g., for x <- c(val = TRUE). Nume

Examples

Example

# NOT RUN {
y <- 1 + (x <- stats::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"

## construct truth tables :

x <- c(NA, FALSE, TRUE)
names(x) <- as.character(x)
outer(x, x, "&") ## AND table
outer(x, x, "|") ## OR  table
# }