ndarray.native.js (1888B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2020 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 Float32Array = require( '@stdlib/array/float32' ); 24 var addon = require( './snanvarianceyc.native.js' ); 25 26 27 // MAIN // 28 29 /** 30 * Computes the variance of a single-precision floating-point strided array ignoring `NaN` values and using a one-pass algorithm proposed by Youngs and Cramer. 31 * 32 * @param {PositiveInteger} N - number of indexed elements 33 * @param {number} correction - degrees of freedom adjustment 34 * @param {Float32Array} x - input array 35 * @param {integer} stride - stride length 36 * @param {NonNegativeInteger} offset - starting index 37 * @returns {number} variance 38 * 39 * @example 40 * var Float32Array = require( '@stdlib/array/float32' ); 41 * var floor = require( '@stdlib/math/base/special/floor' ); 42 * 43 * var x = new Float32Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0, NaN, NaN ] ); 44 * var N = floor( x.length / 2 ); 45 * 46 * var v = snanvarianceyc( N, 1, x, 2, 1 ); 47 * // returns 6.25 48 */ 49 function snanvarianceyc( N, correction, x, stride, offset ) { 50 var view; 51 if ( stride < 0 ) { 52 offset += (N-1) * stride; 53 } 54 view = new Float32Array( x.buffer, x.byteOffset+(x.BYTES_PER_ELEMENT*offset), x.length-offset ); // eslint-disable-line max-len 55 return addon( N, correction, view, stride ); 56 } 57 58 59 // EXPORTS // 60 61 module.exports = snanvarianceyc;