mathjs/src/function/set/setSymDifference.js

51 lines
1.6 KiB
JavaScript

'use strict'
const flatten = require('../../utils/array').flatten
function factory (type, config, load, typed) {
const MatrixIndex = load(require('../../type/matrix/MatrixIndex'))
const concat = load(require('../matrix/concat'))
const size = load(require('../matrix/size'))
const subset = load(require('../matrix/subset'))
const setDifference = load(require('../set/setDifference'))
/**
* Create the symmetric difference of two (multi)sets.
* Multi-dimension arrays will be converted to single-dimension arrays before the operation.
*
* Syntax:
*
* math.setSymDifference(set1, set2)
*
* Examples:
*
* math.setSymDifference([1, 2, 3, 4], [3, 4, 5, 6]) // returns [1, 2, 5, 6]
* math.setSymDifference([[1, 2], [3, 4]], [[3, 4], [5, 6]]) // returns [1, 2, 5, 6]
*
* See also:
*
* setUnion, setIntersect, setDifference
*
* @param {Array | Matrix} a1 A (multi)set
* @param {Array | Matrix} a2 A (multi)set
* @return {Array | Matrix} The symmetric difference of two (multi)sets
*/
const setSymDifference = typed('setSymDifference', {
'Array | Matrix, Array | Matrix': function (a1, a2) {
if (subset(size(a1), new MatrixIndex(0)) === 0) { // if any of them is empty, return the other one
return flatten(a2)
} else if (subset(size(a2), new MatrixIndex(0)) === 0) {
return flatten(a1)
}
const b1 = flatten(a1)
const b2 = flatten(a2)
return concat(setDifference(b1, b2), setDifference(b2, b1))
}
})
return setSymDifference
}
exports.name = 'setSymDifference'
exports.factory = factory