dstdevyc.c (1548B)
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 #include "stdlib/stats/base/dstdevyc.h" 20 #include "stdlib/stats/base/dvarianceyc.h" 21 #include <stdint.h> 22 #include <math.h> 23 24 /** 25 * Computes the standard deviation of a double-precision floating-point strided array using a one-pass algorithm proposed by Youngs and Cramer. 26 * 27 * ## References 28 * 29 * - Youngs, Edward A., and Elliot M. Cramer. 1971. "Some Results Relevant to Choice of Sum and Sum-of-Product Algorithms." _Technometrics_ 13 (3): 657–65. doi:[10.1080/00401706.1971.10488826](https://doi.org/10.1080/00401706.1971.10488826). 30 * 31 * @param N number of indexed elements 32 * @param correction degrees of freedom adjustment 33 * @param X input array 34 * @param stride stride length 35 * @return output value 36 */ 37 double stdlib_strided_dstdevyc( const int64_t N, const double correction, const double *X, const int64_t stride ) { 38 return sqrt( stdlib_strided_dvarianceyc( N, correction, X, stride ) ); 39 }