from_array.js (1378B)
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 isComplexLike = require( '@stdlib/assert/is-complex-like' ); 24 var real = require( '@stdlib/complex/real' ); 25 var imag = require( '@stdlib/complex/imag' ); 26 27 28 // MAIN // 29 30 /** 31 * Returns a strided array of real and imaginary components. 32 * 33 * @private 34 * @param {Float64Array} buf - output array 35 * @param {Array} arr - array containing complex numbers 36 * @returns {(Float64Array|null)} output array or null 37 */ 38 function fromArray( buf, arr ) { 39 var len; 40 var v; 41 var i; 42 var j; 43 44 len = arr.length; 45 j = 0; 46 for ( i = 0; i < len; i++ ) { 47 v = arr[ i ]; 48 if ( !isComplexLike( v ) ) { 49 return null; 50 } 51 buf[ j ] = real( v ); 52 buf[ j+1 ] = imag( v ); 53 j += 2; // stride 54 } 55 return buf; 56 } 57 58 59 // EXPORTS // 60 61 module.exports = fromArray;