xor: Boolean operators and functions

In bit: Classes and Methods for Fast Memory-Efficient Boolean Selections

Boolean operators and functions

Description

Boolean NEGATION '!', AND '&', OR '|' and EXCLUSIVE OR xor', see Logic.

Usage

## Default S3 method:
xor(x, y)

## S3 method for class 'logical'
xor(x, y)

## S3 method for class 'bit'
!x

## S3 method for class 'bit'
e1 & e2

## S3 method for class 'bit'
e1 | e2

## S3 method for class 'bit'
e1 == e2

## S3 method for class 'bit'
e1 != e2

## S3 method for class 'bit'
xor(x, y)

## S3 method for class 'bitwhich'
!x

## S3 method for class 'bitwhich'
e1 & e2

## S3 method for class 'bitwhich'
e1 | e2

## S3 method for class 'bitwhich'
e1 == e2

## S3 method for class 'bitwhich'
e1 != e2

## S3 method for class 'bitwhich'
xor(x, y)

## S3 method for class 'booltype'
e1 & e2

## S3 method for class 'booltype'
e1 | e2

## S3 method for class 'booltype'
e1 == e2

## S3 method for class 'booltype'
e1 != e2

## S3 method for class 'booltype'
xor(x, y)

xor(x, y)

Arguments

x	a is.booltype vector
y	a is.booltype vector
e1	a is.booltype vector
e2	a is.booltype vector

Details

The binary operators and function xor can now combine any is.booltype vectors. They now recycle if vectors have different length. If the two arguments have different booltypes the return value corresponds to the lower booltype of the two.

Boolean operations on bit vectors are extremely fast because they are implemented using C's bitwise operators. Boolean operations on or bitwhich vectors are even faster, if they represent very skewed selections.

The xor function has been made generic and xor.default has been implemented much faster than R's standard xor. This was possible because actually boolean function xor and comparison operator != do the same (even with NAs), and != is much faster than the multiple calls in (x | y) & !(x & y)

Value

An object of class booltype or logical

Methods (by class)

• xor(default): default method for xor

• xor(logical): logical method for xor

• xor(bit): bit method for xor

• xor(bitwhich): bitwhich method for xor

• xor(booltype): booltype method for xor

Functions

• `!`(bit): bit method for !

• & : bit method for &

• | : bit method for |

• == : bit method for ==

• != : bit method for !=

• `!`(bitwhich): bitwhich method for !

• & : bitwhich method for &

• | : bitwhich method for |

• == : bitwhich method for ==

• != : bitwhich method for !=

• & : booltype method for &

• | : booltype method for |

• == : booltype method for ==

• != : booltype method for !=

Author(s)

Jens Oehlschlägel

See Also

booltypes, Logic

Examples

  x <- c(FALSE, FALSE, FALSE, NA, NA, NA, TRUE, TRUE, TRUE)
  y <- c(FALSE, NA, TRUE, FALSE, NA, TRUE, FALSE, NA, TRUE)
  
  x|y
  x|as.bit(y)
  x|as.bitwhich(y)
  x|as.which(y)
  x|ri(1,1,9)
  
  

bit documentation built on Sept. 20, 2024, 5:08 p.m.