testdiff2/SpiriQGC/tools/RandomNumberVerification/gaussian_noise.cpp

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2023-12-06 13:51:14 -04:00
/****************************************************************************
*
* Copyright (C) 2015 PX4 Development Team. All rights reserved.
* Author: Eddy Scott <scott.edward@aurora.aero>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
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****************************************************************************/
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <limits>
#include <iostream> // not needed
#include <fstream> // not needed
using namespace std;
float generateGaussianNoise(float mu, float variance)
{
/* Calculate normally distributed variable noise with mean = mu and variance = variance. Calculated according to
Box-Muller transform */
static const float epsilon = std::numeric_limits<float>::min(); //used to ensure non-zero uniform numbers
static const float two_pi = 2.0*3.14159265358979323846; // 2*pi
static float z0; //calculated normal distribution random variables with mu = 0, var = 1;
float u1, u2; //random variables generated from c++ rand();
/*Generate random variables in range (0 1] */
do
{
u1 = rand() * (1.0 / RAND_MAX);
u2 = rand() * (1.0 / RAND_MAX);
}
while ( u1 <= epsilon ); //Have a catch to ensure non-zero for log()
z0 = sqrt(-2.0 * log(u1)) * cos(two_pi * u2); //calculate normally distributed variable with mu = 0, var = 1
float noise = z0 * sqrt(variance) + mu; //calculate normally distributed variable with mu = mu, std = var^2
return noise;
}
int main(int argc, char *argv[])
{
ofstream fid;
fid.open ("generated_noise.csv");
float mu = atof(argv[1]); // Define the mean of the noise, for gaussian = 0
float variance = atof(argv[2]); //Define the variance of the noise
int num_runs = atoi(argv[3]); //Define number of runs
int num_samples = atoi(argv[4]);
srand(time(NULL)); //Seed rand() function so same random variables are not calculated
cout << "Desired Mean: " << mu << "\n";
cout << "Desired Variance: " << variance << "\n";
cout << "Desired number of runs: " << num_runs << "\n";
cout << "Desired number of samples per run: " << num_samples << "\n";
for(int j=0;j<num_runs;j++){
if(j!=0){
fid <<"\n";
}
for(int i=0;i<num_samples;i++){
fid << generateGaussianNoise(mu, variance) << ",";
}
}
fid.close();
return 0;
}