mathjs/lib/function/arithmetic/floor.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 deepMap = require('../../utils/collection/deepMap');

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

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

function factory(type, config, load, typed) {
  var round = load(require('../../function/arithmetic/round'));
  /**
   * Round a value towards minus infinity.
   * For matrices, the function is evaluated element wise.
   *
   * Syntax:
   *
   *    math.floor(x)
   *
   * Examples:
   *
   *    math.floor(3.2)              // returns number 3
   *    math.floor(3.8)              // returns number 3
   *    math.floor(-4.2)             // returns number -5
   *    math.floor(-4.7)             // returns number -5
   *
   *    const c = math.complex(3.2, -2.7)
   *    math.floor(c)                // returns Complex 3 - 3i
   *
   *    math.floor([3.2, 3.8, -4.7]) // returns Array [3, 3, -5]
   *
   * See also:
   *
   *    ceil, fix, round
   *
   * @param  {number | BigNumber | Fraction | Complex | Array | Matrix} x  Number to be rounded
   * @return {number | BigNumber | Fraction | Complex | Array | Matrix} Rounded value
   */

  var floor = typed('floor', {
    'number': function number(x) {
      if (nearlyEqual(x, round(x), config.epsilon)) {
        return round(x);
      } else {
        return Math.floor(x);
      }
    },
    'Complex': function Complex(x) {
      return x.floor();
    },
    'BigNumber': function BigNumber(x) {
      if (bigNearlyEqual(x, round(x), config.epsilon)) {
        return round(x);
      } else {
        return x.floor();
      }
    },
    'Fraction': function Fraction(x) {
      return x.floor();
    },
    'Array | Matrix': function ArrayMatrix(x) {
      // deep map collection, skip zeros since floor(0) = 0
      return deepMap(x, floor, true);
    }
  });
  floor.toTex = {
    1: "\\left\\lfloor${args[0]}\\right\\rfloor"
  };
  return floor;
}

exports.name = 'floor';
exports.factory = factory;