epsilon.h

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/* -*- mode: C++ -*-
 *
 *  ART epsilon definitions
 *
 *  Copyright (C) 2009 Austin Robot Technology                    
 *  License: Modified BSD Software License Agreement
 *
 *  $Id: epsilon.h 630 2010-09-25 16:20:42Z jack.oquin $
 */

#ifndef _EPSILON_H_
#define _EPSILON_H_

#include <math.h>
#include <angles/angles.h>

namespace Epsilon
{
  const float float_value = 1e-5;       //< minimal float value
  const float distance = 0.01;          //< one centimeter
  const float speed = 0.01;             //< in meters/second
  const float yaw = angles::from_degrees(1.0); //< in radians


  // Slightly better AlmostEqual function – still not recommended
  
  inline bool AlmostEqualRelativeOrAbsolute(float A, float B,
                                     float maxRelativeError, 
                                     float maxAbsoluteError)
  {
    if (fabs(A - B) < maxAbsoluteError)
        return true;

    float relativeError;

    if (fabs(B) > fabs(A))
        relativeError = fabs((A - B) / B);
    else
        relativeError = fabs((A - B) / A);

    if (relativeError <= maxRelativeError)
        return true;

    return false;
}

  inline bool equal(float a, float b) {
    return AlmostEqualRelativeOrAbsolute(a,b,float_value,float_value);
  }

  inline bool lte(float a, float b) {
    return ((a<b) || (equal(a,b)));
  }

  inline bool gte(float a, float b) {
    return ((a>b) || (equal(a,b)));
  }

}

#endif // _EPSILON_H_ //