Colony » Colony Scout » Colony Scout OS

/**

 * Copyright (c) 2011 Colony Project

 * 

 * Permission is hereby granted, free of charge, to any person

 * obtaining a copy of this software and associated documentation

 * files (the "Software"), to deal in the Software without

 * restriction, including without limitation the rights to use,

 * copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following

 * conditions:

 * 

 * The above copyright notice and this permission notice shall be

 * included in all copies or substantial portions of the Software.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

 **/

/**

 * @file noise_gen.c

 * @brief Contains functions that generate noise for scoutsim sensor data

 *

 * Uses central limit theorem to generate gaussian noise.

 *

 * @author Colony Project, CMU Robotics Club

 * @author Priyanka Deo

 **/

#include "noise_gen.h"

#include <stdio.h>

int main()

{

  printf("%f \n", add_gaussian_noise(5, 2));

  printf("%f \n", add_gaussian_noise(5, 2));

  printf("%f \n", add_gaussian_noise(5, 2));

  printf("%f \n", add_gaussian_noise(5, 2));

  printf("%f \n", add_gaussian_noise(5, 2));

}

float add_gaussian_noise(float reading, float max_dev)

{

  float unit_normal = get_unit_normal_random();

  return reading + max_dev*unit_normal;

}

float get_unit_normal_random()

{

  int n=5;

  float sum;

  for(int i=0; i<n; i++)

  {

    sum += rand()/double(RAND_MAX);

    printf("%f \t", sum);

  }

  sum -= (float)n/2.0;

  sum *= 2.0/(float)n;

  return sum;

}