time-to-botec

Benchmark sampling in different programming languages
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cdiv.js (2435B)

      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 'use strict';
     20 
     21 // MODULES //
     22 
     23 var abs = require( './../../../../base/special/abs' );
     24 var max = require( './../../../../base/special/max' );
     25 var FLOAT64_BIGGEST = require( '@stdlib/constants/float64/max' );
     26 var FLOAT64_SMALLEST = require( '@stdlib/constants/float64/smallest-normal' );
     27 var EPS = require( '@stdlib/constants/float64/eps' );
     28 var robustInternal = require( './robust_internal.js' );
     29 
     30 
     31 // VARIABLES //
     32 
     33 var LARGE_THRESHOLD = FLOAT64_BIGGEST * 0.5;
     34 var SMALL_THRESHOLD = FLOAT64_SMALLEST * ( 2.0 / EPS );
     35 var RECIP_EPS_SQR = 2.0 / ( EPS * EPS );
     36 
     37 
     38 // MAIN //
     39 
     40 /**
     41 * Divides two complex numbers.
     42 *
     43 * @private
     44 * @param {(Array|TypedArray|Object)} out - output array
     45 * @param {number} re1 - real component
     46 * @param {number} im1 - imaginary component
     47 * @param {number} re2 - real component
     48 * @param {number} im2 - imaginary component
     49 * @returns {(Array|TypedArray|Object)} output array
     50 *
     51 * @example
     52 * var out = new Array( 2 );
     53 *
     54 * var v = cdiv( out, -13.0, -1.0, -2.0, 1.0 );
     55 * // returns [ 5.0, 3.0 ]
     56 *
     57 * var bool = ( v === out );
     58 * // returns true
     59 */
     60 function cdiv( out, re1, im1, re2, im2 ) {
     61 	var ab;
     62 	var cd;
     63 	var s;
     64 
     65 	ab = max( abs(re1), abs(im1) );
     66 	cd = max( abs(re2), abs(im2) );
     67 	s = 1.0;
     68 
     69 	if ( ab >= LARGE_THRESHOLD ) {
     70 		re1 *= 0.5;
     71 		im1 *= 0.5;
     72 		s *= 2.0;
     73 	} else if ( ab <= SMALL_THRESHOLD ) {
     74 		re1 *= RECIP_EPS_SQR;
     75 		im1 *= RECIP_EPS_SQR;
     76 		s /= RECIP_EPS_SQR;
     77 	}
     78 	if ( cd >= LARGE_THRESHOLD ) {
     79 		re2 *= 0.5;
     80 		im2 *= 0.5;
     81 		s *= 0.5;
     82 	} else if ( cd <= SMALL_THRESHOLD ) {
     83 		re2 *= RECIP_EPS_SQR;
     84 		im2 *= RECIP_EPS_SQR;
     85 		s *= RECIP_EPS_SQR;
     86 	}
     87 	if ( abs( im2 ) <= abs( re2 ) ) {
     88 		robustInternal( out, re1, im1, re2, im2 );
     89 	} else {
     90 		robustInternal( out, im1, re1, im2, re2 );
     91 		out[ 1 ] *= -1;
     92 	}
     93 	out[ 0 ] *= s;
     94 	out[ 1 ] *= s;
     95 	return out;
     96 }
     97 
     98 
     99 // EXPORTS //
    100 
    101 module.exports = cdiv;