Deming's funnel: Difference between revisions

=={{header|C++}}==

<syntaxhighlight lang="c++">

#include <cmath>

#include <functional>

#include <iomanip>

#include <iostream>

#include <string>

#include <vector>

double mean(const std::vector<double>& pseudo_random) {

double sum = 0.0;

for ( double item : pseudo_random ) {

sum += item;

}

return sum / pseudo_random.size();

}

double standard_deviation(const std::vector<double>& pseudo_random) {

const double average = mean(pseudo_random);

double sum_squares = 0.0;

for ( double item : pseudo_random ) {

sum_squares += item * item;

}

return sqrt(sum_squares / pseudo_random.size() - average * average);

}

std::vector<double> funnel(const std::vector<double>& pseudo_random, const std::function<double(double, double)>& rule) {

double value = 0.0;

std::vector<double> result(pseudo_random.size(), 0);

for ( size_t i = 0; i < pseudo_random.size(); i++ ) {

const double result_value = value + pseudo_random[i];

value = rule(value, pseudo_random[i]);

result[i] = result_value;

}

return result;

}

void experiment(const std::string& label, const std::vector<double>& pseudo_random_xs,

const std::vector<double>& pseudo_random_ys, const std::function<double(double, double)>& rule) {

std::vector<double> result_x = funnel(pseudo_random_xs, rule);

std::vector<double> result_y = funnel(pseudo_random_ys, rule);

std::cout << label << std::endl;

std::cout << "-----------------------------------------" << std::endl;

std::cout << "Mean x, y" << std::setw(16) << ": " << std::fixed << std::setprecision(4)

<< mean(result_x) << ", " << mean(result_y) << std::endl;

std::cout << "Standard deviation x, y: " << standard_deviation(result_x) << ", "

<< standard_deviation(result_y) << std::endl;

std::cout << std::endl;

}

int main() {

const std::vector<double> pseudo_random_xs = { -0.533, 0.270, 0.859, -0.043, -0.205, -0.127, -0.071,

0.275, 1.251, -0.231, -0.401, 0.269, 0.491, 0.951, 1.150, 0.001, -0.382, 0.161, 0.915, 2.080, -2.337,

0.034, -0.126, 0.014, 0.709, 0.129, -1.093, -0.483, -1.193, 0.020, -0.051, 0.047, -0.095, 0.695, 0.340,

-0.182, 0.287, 0.213, -0.423, -0.021, -0.134, 1.798, 0.021, -1.099, -0.361, 1.636, -1.134, 1.315,

0.201, 0.034, 0.097, -0.170, 0.054, -0.553, -0.024, -0.181, -0.700, -0.361, -0.789, 0.279, -0.174,

-0.009, -0.323, -0.658, 0.348, -0.528, 0.881, 0.021, -0.853, 0.157, 0.648, 1.774, -1.043, 0.051,

0.021, 0.247, -0.310, 0.171, 0.000, 0.106, 0.024, -0.386, 0.962, 0.765, -0.125, -0.289, 0.521,

0.017, 0.281, -0.749, -0.149, -2.436, -0.909, 0.394, -0.113, -0.598, 0.443, -0.521, -0.799, 0.087 };

const std::vector<double> pseudo_random_ys = { 0.136, 0.717, 0.459, -0.225, 1.392, 0.385, 0.121, -0.395,

0.490, -0.682, -0.065, 0.242, -0.288, 0.658, 0.459, 0.000, 0.426, 0.205, -0.765, -2.188, -0.742,

-0.010, 0.089, 0.208, 0.585, 0.633, -0.444, -0.351, -1.087, 0.199, 0.701, 0.096, -0.025, -0.868, 1.051,

0.157, 0.216, 0.162, 0.249, -0.007, 0.009, 0.508, -0.790, 0.723, 0.881, -0.508, 0.393, -0.226, 0.710,

0.038, -0.217, 0.831, 0.480, 0.407, 0.447, -0.295, 1.126, 0.380, 0.549, -0.445, -0.046, 0.428, -0.074,

0.217, -0.822, 0.491, 1.347, -0.141, 1.230, -0.044, 0.079, 0.219, 0.698, 0.275, 0.056, 0.031, 0.421, 0.064,

0.721, 0.104, -0.729, 0.650, -1.103, 0.154, -1.720, 0.051, -0.385, 0.477, 1.537, -0.901, 0.939, -0.411,

0.341, -0.411, 0.106, 0.224, -0.947, -1.424, -0.542, -1.032 };

experiment("Rule 1:", pseudo_random_xs, pseudo_random_ys, [](double z, double dz) -> double { return 0.0; });

experiment("Rule 2:", pseudo_random_xs, pseudo_random_ys, [](double z, double dz) -> double { return -dz; });

experiment("Rule 3:", pseudo_random_xs, pseudo_random_ys, [](double z, double dz) -> double { return -( z + dz ); });

experiment("Rule 4:", pseudo_random_xs, pseudo_random_ys, [](double z, double dz) -> double { return z + dz; });

}

</syntaxhighlight>

{{ out }}

<pre>

Rule 1:

-----------------------------------------

Mean x, y : 0.0004, 0.0702

Standard deviation x, y: 0.7153, 0.6462

Rule 2:

-----------------------------------------

Mean x, y : 0.0009, -0.0103

Standard deviation x, y: 1.0371, 0.8999

Rule 3:

-----------------------------------------

Mean x, y : 0.0439, -0.0063

Standard deviation x, y: 7.9871, 4.7784

Rule 4:

-----------------------------------------

Mean x, y : 3.1341, 5.4210

Standard deviation x, y: 1.5874, 3.9304

</pre>