mathjs/lib/function/relational/unequal.js

Math.js is an extensive math library for JavaScript and Node.js. It features a flexible expression parser with support for symbolic computation, comes with a large set of built-in functions and constants, and offers an integrated solution to work with dif

'use strict';

var nearlyEqual = require('../../utils/number').nearlyEqual;

var bigNearlyEqual = require('../../utils/bignumber/nearlyEqual');

function factory(type, config, load, typed) {
  var matrix = load(require('../../type/matrix/function/matrix'));
  var algorithm03 = load(require('../../type/matrix/utils/algorithm03'));
  var algorithm07 = load(require('../../type/matrix/utils/algorithm07'));
  var algorithm12 = load(require('../../type/matrix/utils/algorithm12'));
  var algorithm13 = load(require('../../type/matrix/utils/algorithm13'));
  var algorithm14 = load(require('../../type/matrix/utils/algorithm14'));

  var latex = require('../../utils/latex');
  /**
   * Test whether two values are unequal.
   *
   * The function tests whether the relative difference between x and y is
   * larger than the configured epsilon. The function cannot be used to compare
   * values smaller than approximately 2.22e-16.
   *
   * For matrices, the function is evaluated element wise.
   * In case of complex numbers, x.re must unequal y.re, or x.im must unequal y.im.
   * Strings are compared by their numerical value.
   *
   * Values `null` and `undefined` are compared strictly, thus `null` is unequal
   * with everything except `null`, and `undefined` is unequal with everything
   * except `undefined`.
   *
   * Syntax:
   *
   *    math.unequal(x, y)
   *
   * Examples:
   *
   *    math.unequal(2 + 2, 3)       // returns true
   *    math.unequal(2 + 2, 4)       // returns false
   *
   *    const a = math.unit('50 cm')
   *    const b = math.unit('5 m')
   *    math.unequal(a, b)           // returns false
   *
   *    const c = [2, 5, 1]
   *    const d = [2, 7, 1]
   *
   *    math.unequal(c, d)           // returns [false, true, false]
   *    math.deepEqual(c, d)         // returns false
   *
   *    math.unequal(0, null)        // returns true
   * See also:
   *
   *    equal, deepEqual, smaller, smallerEq, larger, largerEq, compare
   *
   * @param  {number | BigNumber | Fraction | boolean | Complex | Unit | string | Array | Matrix | undefined} x First value to compare
   * @param  {number | BigNumber | Fraction | boolean | Complex | Unit | string | Array | Matrix | undefined} y Second value to compare
   * @return {boolean | Array | Matrix} Returns true when the compared values are unequal, else returns false
   */


  var unequal = typed('unequal', {
    'any, any': function anyAny(x, y) {
      // strict equality for null and undefined?
      if (x === null) {
        return y !== null;
      }

      if (y === null) {
        return x !== null;
      }

      if (x === undefined) {
        return y !== undefined;
      }

      if (y === undefined) {
        return x !== undefined;
      }

      return _unequal(x, y);
    },
    'SparseMatrix, SparseMatrix': function SparseMatrixSparseMatrix(x, y) {
      return algorithm07(x, y, _unequal);
    },
    'SparseMatrix, DenseMatrix': function SparseMatrixDenseMatrix(x, y) {
      return algorithm03(y, x, _unequal, true);
    },
    'DenseMatrix, SparseMatrix': function DenseMatrixSparseMatrix(x, y) {
      return algorithm03(x, y, _unequal, false);
    },
    'DenseMatrix, DenseMatrix': function DenseMatrixDenseMatrix(x, y) {
      return algorithm13(x, y, _unequal);
    },
    'Array, Array': function ArrayArray(x, y) {
      // use matrix implementation
      return unequal(matrix(x), matrix(y)).valueOf();
    },
    'Array, Matrix': function ArrayMatrix(x, y) {
      // use matrix implementation
      return unequal(matrix(x), y);
    },
    'Matrix, Array': function MatrixArray(x, y) {
      // use matrix implementation
      return unequal(x, matrix(y));
    },
    'SparseMatrix, any': function SparseMatrixAny(x, y) {
      return algorithm12(x, y, _unequal, false);
    },
    'DenseMatrix, any': function DenseMatrixAny(x, y) {
      return algorithm14(x, y, _unequal, false);
    },
    'any, SparseMatrix': function anySparseMatrix(x, y) {
      return algorithm12(y, x, _unequal, true);
    },
    'any, DenseMatrix': function anyDenseMatrix(x, y) {
      return algorithm14(y, x, _unequal, true);
    },
    'Array, any': function ArrayAny(x, y) {
      // use matrix implementation
      return algorithm14(matrix(x), y, _unequal, false).valueOf();
    },
    'any, Array': function anyArray(x, y) {
      // use matrix implementation
      return algorithm14(matrix(y), x, _unequal, true).valueOf();
    }
  });

  var _unequal = typed('_unequal', {
    'boolean, boolean': function booleanBoolean(x, y) {
      return x !== y;
    },
    'number, number': function numberNumber(x, y) {
      return !nearlyEqual(x, y, config.epsilon);
    },
    'BigNumber, BigNumber': function BigNumberBigNumber(x, y) {
      return !bigNearlyEqual(x, y, config.epsilon);
    },
    'Fraction, Fraction': function FractionFraction(x, y) {
      return !x.equals(y);
    },
    'Complex, Complex': function ComplexComplex(x, y) {
      return !x.equals(y);
    },
    'Unit, Unit': function UnitUnit(x, y) {
      if (!x.equalBase(y)) {
        throw new Error('Cannot compare units with different base');
      }

      return unequal(x.value, y.value);
    }
  });

  unequal.toTex = {
    2: "\\left(${args[0]}".concat(latex.operators['unequal'], "${args[1]}\\right)")
  };
  return unequal;
}

exports.name = 'unequal';
exports.factory = factory;