mirror of
https://github.com/josdejong/mathjs.git
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85 lines
2.3 KiB
JavaScript
85 lines
2.3 KiB
JavaScript
'use strict';
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var flatten = require('../../utils/array').flatten;
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function factory (type, config, load, typed) {
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var abs = load(require('./abs'));
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var add = load(require('./addScalar'));
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var divide = load(require('./divideScalar'));
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var multiply = load(require('./multiplyScalar'));
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var sqrt = load(require('./sqrt'));
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var smaller = load(require('../relational/smaller'));
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var isPositive = load(require('../utils/isPositive'));
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/**
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* Calculate the hypotenusa of a list with values. The hypotenusa is defined as:
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*
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* hypot(a, b, c, ...) = sqrt(a^2 + b^2 + c^2 + ...)
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*
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* For matrix input, the hypotenusa is calculated for all values in the matrix.
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*
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* Syntax:
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*
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* math.hypot(a, b, ...)
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* math.hypot([a, b, c, ...])
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*
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* Examples:
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*
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* math.hypot(3, 4); // 5
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* math.hypot(3, 4, 5); // 7.0710678118654755
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* math.hypot([3, 4, 5]); // 7.0710678118654755
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* math.hypot(-2); // 2
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*
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* See also:
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*
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* abs, norm
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*
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* @param {... number | BigNumber} args
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* @return {number | BigNumber} Returns the hypothenusa of the input values.
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*/
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var hypot = typed('hypot', {
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'... number | BigNumber': _hypot,
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'Array': function (x) {
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return hypot.apply(hypot, flatten(x));
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},
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'Matrix': function (x) {
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return hypot.apply(hypot, flatten(x.toArray()));
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}
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});
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/**
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* Calculate the hypotenusa for an Array with values
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* @param {Array.<number | BigNumber>} args
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* @return {number | BigNumber} Returns the result
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* @private
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*/
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function _hypot (args) {
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// code based on `hypot` from es6-shim:
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// https://github.com/paulmillr/es6-shim/blob/master/es6-shim.js#L1619-L1633
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var result = 0;
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var largest = 0;
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for (var i = 0; i < args.length; i++) {
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var value = abs(args[i]);
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if (smaller(largest, value)) {
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result = multiply(result, multiply(divide(largest, value), divide(largest, value)));
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result = add(result, 1);
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largest = value;
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} else {
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result = add(result, isPositive(value) ? multiply(divide(value, largest), divide(value, largest)) : value);
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}
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}
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return multiply(largest, sqrt(result));
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}
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hypot.toTex = '\\hypot\\left(${args}\\right)';
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return hypot;
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}
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exports.name = 'hypot';
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exports.factory = factory;
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