rational_p2q2.js (2492B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 The Stdlib Authors. 5 * 6 * Licensed under the Apache License, Version 2.0 (the "License"); 7 * you may not use this file except in compliance with the License. 8 * You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 /* This is a generated file. Do not edit directly. */ 20 'use strict'; 21 22 // MAIN // 23 24 /** 25 * Evaluates a rational function, i.e., the ratio of two polynomials described by the coefficients stored in \\(P\\) and \\(Q\\). 26 * 27 * ## Notes 28 * 29 * - Coefficients should be sorted in ascending degree. 30 * - The implementation uses [Horner's rule][horners-method] for efficient computation. 31 * 32 * [horners-method]: https://en.wikipedia.org/wiki/Horner%27s_method 33 * 34 * 35 * @private 36 * @param {number} x - value at which to evaluate the rational function 37 * @returns {number} evaluated rational function 38 */ 39 function evalrational( x ) { 40 var ax; 41 var s1; 42 var s2; 43 if ( x === 0.0 ) { 44 return -0.010158790774176108; 45 } 46 if ( x < 0.0 ) { 47 ax = -x; 48 } else { 49 ax = x; 50 } 51 if ( ax <= 1.0 ) { 52 s1 = -17527881995806512.0 + (x * (1660853173129901.8 + (x * (-36658018905416.664 + (x * (355806656709.1062 + (x * (-1811393126.9860668 + (x * (5079326.614801118 + (x * (-7502.334222078161 + (x * 4.6179191852758255))))))))))))); // eslint-disable-line max-len 53 s2 = 1725390588844768000.0 + (x * (17128800897135812.0 + (x * (84899346165481.42 + (x * (276227772862.44086 + (x * (648725028.9959639 + (x * (1126712.5065029138 + (x * (1388.6978985861358 + (x * 1.0))))))))))))); // eslint-disable-line max-len 54 } else { 55 x = 1.0 / x; 56 s1 = 4.6179191852758255 + (x * (-7502.334222078161 + (x * (5079326.614801118 + (x * (-1811393126.9860668 + (x * (355806656709.1062 + (x * (-36658018905416.664 + (x * (1660853173129901.8 + (x * -17527881995806512.0))))))))))))); // eslint-disable-line max-len 57 s2 = 1.0 + (x * (1388.6978985861358 + (x * (1126712.5065029138 + (x * (648725028.9959639 + (x * (276227772862.44086 + (x * (84899346165481.42 + (x * (17128800897135812.0 + (x * 1725390588844768000.0))))))))))))); // eslint-disable-line max-len 58 } 59 return s1 / s2; 60 } 61 62 63 // EXPORTS // 64 65 module.exports = evalrational;