/** * @license Apache-2.0 * * Copyright (c) 2020 The Stdlib Authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ 'use strict'; // MODULES // var Float32Array = require( '@stdlib/array/float32' ); var addon = require( './sstdevwd.native.js' ); // MAIN // /** * Computes the standard deviation of a single-precision floating-point strided array using Welford's algorithm. * * @param {PositiveInteger} N - number of indexed elements * @param {number} correction - degrees of freedom adjustment * @param {Float32Array} x - input array * @param {integer} stride - stride length * @param {NonNegativeInteger} offset - starting index * @returns {number} standard deviation * * @example * var Float32Array = require( '@stdlib/array/float32' ); * var floor = require( '@stdlib/math/base/special/floor' ); * * var x = new Float32Array( [ 2.0, 1.0, 2.0, -2.0, -2.0, 2.0, 3.0, 4.0 ] ); * var N = floor( x.length / 2 ); * * var v = sstdevwd( N, 1, x, 2, 1 ); * // returns 2.5 */ function sstdevwd( N, correction, x, stride, offset ) { var view; if ( stride < 0 ) { offset += (N-1) * stride; } view = new Float32Array( x.buffer, x.byteOffset+(x.BYTES_PER_ELEMENT*offset), x.length-offset ); // eslint-disable-line max-len return addon( N, correction, view, stride ); } // EXPORTS // module.exports = sstdevwd;