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/*
**************************************************************
* C++ Mathematical Expression Toolkit Library *
* *
* Simple Example 14 *
* Author: Arash Partow (1999-2024) *
* URL: https://www.partow.net/programming/exprtk/index.html *
* *
* Copyright notice: *
* Free use of the Mathematical Expression Toolkit Library is *
* permitted under the guidelines and in accordance with the *
* most current version of the MIT License. *
* https://www.opensource.org/licenses/MIT *
* SPDX-License-Identifier: MIT *
* *
**************************************************************
*/
#include <cstdio>
#include <string>
#include "exprtk.hpp"
template <typename T>
void stddev_example()
{
typedef exprtk::expression<T> expression_t;
typedef exprtk::parser<T> parser_t;
const std::string stddev_program =
" var x[25] := { "
" 1, 2, 3, 4, 5, "
" 6, 7, 8, 9, 10, "
" 11, 12, 13, 14, 15, "
" 16, 17, 18, 19, 20, "
" 21, 22, 23, 24, 25 "
" }; "
" "
" sqrt(sum([x - avg(x)]^2) / x[]) ";
expression_t expression;
parser_t parser;
parser.compile(stddev_program,expression);
const T stddev = expression.value();
printf("stddev(1..25) = %10.6f\n",stddev);
}
int main()
{
stddev_example<double>();
return 0;
}
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