Attachment #735 for bug #787

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private:
  virtual bool DoRun (void);

  typedef struct
  {
    Vector m_position;
    double m_pt;  // dBm
    double m_pr;  // W

};

FriisPropagationLossModelTestCase::FriisPropagationLossModelTestCase ()
  : TestCase ("Check to see that the ns-3 Friis propagation loss model provides correct received power"),
    m_testVectors ()
{
}


      testVector = m_testVectors.Get (i);
      b->SetPosition (testVector.m_position);
      double resultdBm = lossModel->CalcRxPower (testVector.m_pt, a, b);
      double resultW =   pow (10.0, resultdBm / 10.0) / 1000;
      NS_TEST_EXPECT_MSG_EQ_TOL (resultW, testVector.m_pr, testVector.m_tolerance, "Got unexpected rcv power");
    }
	
  return GetErrorStatus ();
}

// Added for Two-Ray Ground Model - tomhewer@mac.com

class TwoRayGroundPropagationLossModelTestCase : public TestCase
{
public:
  TwoRayGroundPropagationLossModelTestCase ();
  virtual ~TwoRayGroundPropagationLossModelTestCase ();

private:
  virtual bool DoRun (void);

  typedef struct
  {
    Vector m_position;
    double m_pt;  // dBm
    double m_pr;  // W
    double m_tolerance;
  } TestVector;

  TestVectors<TestVector> m_testVectors;
};

TwoRayGroundPropagationLossModelTestCase::TwoRayGroundPropagationLossModelTestCase ()
  : TestCase ("Check to see that the ns-3 TwoRayGround propagation loss model provides correct received power"),
    m_testVectors ()
{
}

TwoRayGroundPropagationLossModelTestCase::~TwoRayGroundPropagationLossModelTestCase ()
{
}

bool
TwoRayGroundPropagationLossModelTestCase::DoRun (void)
{
  // wavelength at 2.4 GHz is 0.125m
  Config::SetDefault ("ns3::TwoRayGroundPropagationLossModel::Lambda", DoubleValue (0.125));
  Config::SetDefault ("ns3::TwoRayGroundPropagationLossModel::SystemLoss", DoubleValue (1.0));

  // set antenna height to 1.5m above z coordinate
  Config::SetDefault ("ns3::TwoRayGroundPropagationLossModel::HeightAboveZ", DoubleValue (1.5));

  // Select a reference transmit power of 17.0206 dBm
  // Pt = 10^(17.0206/10)/10^3 = .05035702 W
  double txPowerW = 0.05035702;
  double txPowerdBm = 10 * log10 (txPowerW) + 30;

  //
  // As with the Friis tests above, we want to test the propagation loss 
  // model calculations at a few chosen distances and compare the results 
  // to those we can manually calculate. Let us test the ns-3 calculated 
  // value for agreement to be within 5e-16, as above.
  //
  TestVector testVector;

  // Below the Crossover distance use Friis so this test should be the same as that above
  // Crossover = (4 * PI * TxAntennaHeight * RxAntennaHeight) / Lamdba
  // Crossover = (4 * PI * 1.5 * 1.5) / 0.125 = 226.1946m

  testVector.m_position = Vector (100, 0, 0);
  testVector.m_pt = txPowerdBm;
  testVector.m_pr = 4.98265e-10;
  testVector.m_tolerance = 5e-16;
  m_testVectors.Add (testVector);

  // These values are above the crossover distance and therefore use the Two Ray calculation

  testVector.m_position = Vector (500, 0, 0);
  testVector.m_pt = txPowerdBm;
  testVector.m_pr = 4.07891862e-12;
  testVector.m_tolerance = 5e-16;
  m_testVectors.Add (testVector);

  testVector.m_position = Vector (1000, 0, 0);
  testVector.m_pt = txPowerdBm;
  testVector.m_pr = 2.5493241375e-13;
  testVector.m_tolerance = 5e-16;
  m_testVectors.Add (testVector);

  testVector.m_position = Vector (2000, 0, 0);
  testVector.m_pt = txPowerdBm;
  testVector.m_pr = 1.593327585938e-14;
  testVector.m_tolerance = 5e-16;
  m_testVectors.Add (testVector);

  // Repeat the tests for non-zero z coordinates

  // Pr = (0.05035702 * (1.5*1.5) * (2.5*2.5)) / (500*500*500*500) = 1.13303295e-11
  // dCross = (4 * pi * 1.5 * 2.5) / 0.125 = 376.99m
  testVector.m_position = Vector (500, 0, 1);
  testVector.m_pt = txPowerdBm;
  testVector.m_pr = 1.13303295e-11;
  testVector.m_tolerance = 5e-16;
  m_testVectors.Add (testVector);

  // Pr = (0.05035702 * (1.5*1.5) * (5.5*5.5)) / (1000*1000*1000*1000) = 3.42742467375e-12
  // dCross = (4 * pi * 1.5 * 5.5) / 0.125 = 829.38m
  testVector.m_position = Vector (1000, 0, 4);
  testVector.m_pt = txPowerdBm;
  testVector.m_pr = 3.42742467375e-12;
  testVector.m_tolerance = 5e-16;
  m_testVectors.Add (testVector);

  // Pr = (0.05035702 * (1.5*1.5) * (11.5*11.5)) / (2000*2000*2000*2000) = 9.36522547734e-13
  // dCross = (4 * pi * 1.5 * 11.5) / 0.125 = 1734.15m
  testVector.m_position = Vector (2000, 0, 10);
  testVector.m_pt = txPowerdBm;
  testVector.m_pr = 9.36522547734e-13;
  testVector.m_tolerance = 5e-16;
  m_testVectors.Add (testVector);


  // Now, check that the received power values are expected

  Ptr<MobilityModel> a = CreateObject<ConstantPositionMobilityModel> (); 
  a->SetPosition (Vector (0,0,0));
  Ptr<MobilityModel> b = CreateObject<ConstantPositionMobilityModel> (); 

  Ptr<TwoRayGroundPropagationLossModel> lossModel = CreateObject<TwoRayGroundPropagationLossModel> (); 
  for (uint32_t i = 0; i < m_testVectors.GetN (); ++i)
    {
      testVector = m_testVectors.Get (i);
      b->SetPosition (testVector.m_position);
      double resultdBm = lossModel->CalcRxPower (testVector.m_pt, a, b);
      double resultW =   pow (10.0, resultdBm / 10.0) / 1000;
      NS_TEST_EXPECT_MSG_EQ_TOL (resultW, testVector.m_pr, testVector.m_tolerance, "Got unexpected rcv power");
    }

  return GetErrorStatus ();
}


private:
  virtual bool DoRun (void);

  typedef struct
  {
    Vector m_position;
    double m_pt;  // dBm
    double m_pr;  // W

};

LogDistancePropagationLossModelTestCase::LogDistancePropagationLossModelTestCase ()
  : TestCase ("Check to see that the ns-3 Log Distance propagation loss model provides correct received power"),
    m_testVectors ()
{
}


      testVector = m_testVectors.Get (i);
      b->SetPosition (testVector.m_position);
      double resultdBm = lossModel->CalcRxPower (testVector.m_pt, a, b);
      double resultW =   pow (10.0, resultdBm / 10.0) / 1000;
      NS_TEST_EXPECT_MSG_EQ_TOL (resultW, testVector.m_pr, testVector.m_tolerance, "Got unexpected rcv power");
    }
	

  : TestSuite ("propagation-loss-model", UNIT)
{
  AddTestCase (new FriisPropagationLossModelTestCase);
  AddTestCase (new TwoRayGroundPropagationLossModelTestCase);
  AddTestCase (new LogDistancePropagationLossModelTestCase);
}





 *
 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
 * Contributions: Timo Bingmann <timo.bingmann@student.kit.edu>
 * Contributions: Tom Hewer <tomhewer@mac.com> for Two Ray Ground Model
 */

#include "propagation-loss-model.h"

{
  static TypeId tid = TypeId ("ns3::PropagationLossModel")
    .SetParent<Object> ()
  ;
  return tid;
}

PropagationLossModel::PropagationLossModel ()
  : m_next (0)
{
}

PropagationLossModel::~PropagationLossModel ()
{
}

void
PropagationLossModel::SetNext (Ptr<PropagationLossModel> next)
{
  m_next = next;
}

double
PropagationLossModel::CalcRxPower (double txPowerDbm,
                                   Ptr<MobilityModel> a,
                                   Ptr<MobilityModel> b) const

                   RandomVariableValue (ConstantVariable (1.0)),
                   MakeRandomVariableAccessor (&RandomPropagationLossModel::m_variable),
                   MakeRandomVariableChecker ())
  ;
  return tid;
}
RandomPropagationLossModel::RandomPropagationLossModel ()
  : PropagationLossModel ()
{
}

RandomPropagationLossModel::~RandomPropagationLossModel ()
{
}

double
RandomPropagationLossModel::DoCalcRxPower (double txPowerDbm,
                                           Ptr<MobilityModel> a,
                                           Ptr<MobilityModel> b) const
{
  double rxc = -m_variable.GetValue ();
  NS_LOG_DEBUG ("attenuation coefficent=" << rxc << "Db");
  return txPowerDbm + rxc;
}


                   MakeDoubleAccessor (&FriisPropagationLossModel::SetMinDistance,
                                       &FriisPropagationLossModel::GetMinDistance),
                   MakeDoubleChecker<double> ())
  ;
  return tid;
}

FriisPropagationLossModel::FriisPropagationLossModel ()
{
}
void
FriisPropagationLossModel::SetSystemLoss (double systemLoss)
{
  m_systemLoss = systemLoss;
}
double
FriisPropagationLossModel::GetSystemLoss (void) const
{
  return m_systemLoss;
}
void
FriisPropagationLossModel::SetMinDistance (double minDistance)
{
  m_minDistance = minDistance;
}
double
FriisPropagationLossModel::GetMinDistance (void) const
{
  return m_minDistance;
}
void
FriisPropagationLossModel::SetLambda (double frequency, double speed)
{
  m_lambda = speed / frequency;
}
void
FriisPropagationLossModel::SetLambda (double lambda)
{
  m_lambda = lambda;
}
double
FriisPropagationLossModel::GetLambda (void) const
{
  return m_lambda;
}

double
FriisPropagationLossModel::DbmToW (double dbm) const
{
  double mw = pow (10.0,dbm / 10.0);
  return mw / 1000.0;
}


  double numerator = m_lambda * m_lambda;
  double denominator = 16 * PI * PI * distance * distance * m_systemLoss;
  double pr = 10 * log10 (numerator / denominator);
  NS_LOG_DEBUG ("distance=" << distance << "m, attenuation coefficient=" << pr << "dB");
  return txPowerDbm + pr;
}

// ------------------------------------------------------------------------- //
// -- Two-Ray Ground Model ported from NS-2 -- tomhewer@mac.com -- Nov09 //

NS_OBJECT_ENSURE_REGISTERED (TwoRayGroundPropagationLossModel);

const double TwoRayGroundPropagationLossModel::PI = 3.14159265358979323846;

TypeId 
TwoRayGroundPropagationLossModel::GetTypeId (void)
{
  static TypeId tid = TypeId ("ns3::TwoRayGroundPropagationLossModel")
    .SetParent<PropagationLossModel> ()
    .AddConstructor<TwoRayGroundPropagationLossModel> ()
    .AddAttribute ("Lambda",
                   "The wavelength  (default is 5.15 GHz at 300 000 km/s).",
                   DoubleValue (300000000.0 / 5.150e9),
                   MakeDoubleAccessor (&TwoRayGroundPropagationLossModel::m_lambda),
                   MakeDoubleChecker<double> ())
    .AddAttribute ("SystemLoss", "The system loss",
                   DoubleValue (1.0),
                   MakeDoubleAccessor (&TwoRayGroundPropagationLossModel::m_systemLoss),
                   MakeDoubleChecker<double> ())
    .AddAttribute ("MinDistance",
                   "The distance under which the propagation model refuses to give results (m)",
                   DoubleValue (0.5),
                   MakeDoubleAccessor (&TwoRayGroundPropagationLossModel::SetMinDistance,
                                       &TwoRayGroundPropagationLossModel::GetMinDistance),
                   MakeDoubleChecker<double> ())
    .AddAttribute ("HeightAboveZ",
                   "The height of the antenna (m) above the node's Z coordinate",
                   DoubleValue (0),
                   MakeDoubleAccessor (&TwoRayGroundPropagationLossModel::m_heightAboveZ),
                   MakeDoubleChecker<double> ())
  ;
  return tid;
}

TwoRayGroundPropagationLossModel::TwoRayGroundPropagationLossModel ()
{
}
void
TwoRayGroundPropagationLossModel::SetSystemLoss (double systemLoss)
{
  m_systemLoss = systemLoss;
}
double
TwoRayGroundPropagationLossModel::GetSystemLoss (void) const
{
  return m_systemLoss;
}
void
TwoRayGroundPropagationLossModel::SetMinDistance (double minDistance)
{
  m_minDistance = minDistance;
}
double
TwoRayGroundPropagationLossModel::GetMinDistance (void) const
{
  return m_minDistance;
}
void
TwoRayGroundPropagationLossModel::SetHeightAboveZ (double heightAboveZ)
{
  m_heightAboveZ = heightAboveZ;
}
void 
TwoRayGroundPropagationLossModel::SetLambda (double frequency, double speed)
{
  m_lambda = speed / frequency;
}
void 
TwoRayGroundPropagationLossModel::SetLambda (double lambda)
{
  m_lambda = lambda;
}
double 
TwoRayGroundPropagationLossModel::GetLambda (void) const
{
  return m_lambda;
}

double 
TwoRayGroundPropagationLossModel::DbmToW (double dbm) const
{
  double mw = pow (10.0,dbm / 10.0);
  return mw / 1000.0;
}

double
TwoRayGroundPropagationLossModel::DbmFromW (double w) const
{
  double dbm = log10 (w * 1000.0) * 10.0;
  return dbm;
}

double 
TwoRayGroundPropagationLossModel::DoCalcRxPower (double txPowerDbm,
                                                 Ptr<MobilityModel> a,
                                                 Ptr<MobilityModel> b) const
{
  /*
   * Two-Ray Ground equation:
   *
   * where Pt, Gt and Gr are in dBm units
   * L, Ht and Hr are in meter units.
   *
   *   Pr      Gt * Gr * (Ht^2 * Hr^2)
   *   -- =  (-------------------------)
   *	 Pt            d^4 * L
   *
   * Gt: tx gain (unit-less)
   * Gr: rx gain (unit-less)
   * Pt: tx power (dBm)
   * d: distance (m)
   * L: system loss
   * Ht: Tx antenna height (m)
   * Hr: Rx antenna height (m)
   * lambda: wavelength (m)
   *
   * As with the Friis model we ignore tx and rx gain and output values
   * are in dB or dBm
   *
   *						  (Ht * Ht) * (Hr * Hr)
   * rx = tx + 10 log10	(-----------------------)
   *						   (d * d * d * d) * L
   */
  double distance = a->GetDistanceFrom (b);
  if (distance <= m_minDistance)
    {
      return txPowerDbm;
    }

  // Set the height of the Tx and Rx antennae
  double txAntHeight = a->GetPosition ().z + m_heightAboveZ;
  double rxAntHeight = b->GetPosition ().z + m_heightAboveZ;

  // Calculate a crossover distance, under which we use Friis
  /*
   * 
   * dCross = (4 * pi * Ht * Hr) / lambda
   *
   */

  double dCross = (4 * PI * txAntHeight * rxAntHeight) / GetLambda ();
  double tmp = 0;
  if (distance <= dCross)
    {
      // We use Friis
      double numerator = m_lambda * m_lambda;
      tmp = PI * distance;
      double denominator = 16 * tmp * tmp * m_systemLoss;
      double pr = 10 * log10 (numerator / denominator);
      NS_LOG_DEBUG ("Receiver within crossover (" << dCross << "m) for Two_ray path; using Friis");
      NS_LOG_DEBUG ("distance=" << distance << "m, attenuation coefficient=" << pr << "dB");
      return txPowerDbm + pr;
    }
  else   // Use Two-Ray Pathloss
    {
      tmp = txAntHeight * rxAntHeight;
      double rayNumerator = tmp * tmp;
      tmp = distance * distance;
      double rayDenominator = tmp * tmp * m_systemLoss;
      double rayPr = 10 * log10 (rayNumerator / rayDenominator);
      NS_LOG_DEBUG ("distance=" << distance << "m, attenuation coefficient=" << rayPr << "dB");
      return txPowerDbm + rayPr;

    }
}

// ------------------------------------------------------------------------- //

                   DoubleValue (46.6777),
                   MakeDoubleAccessor (&LogDistancePropagationLossModel::m_referenceLoss),
                   MakeDoubleChecker<double> ())
  ;
  return tid;

}

LogDistancePropagationLossModel::LogDistancePropagationLossModel ()
{
}

void
LogDistancePropagationLossModel::SetPathLossExponent (double n)
{
  m_exponent = n;
}
void
LogDistancePropagationLossModel::SetReference (double referenceDistance, double referenceLoss)
{
  m_referenceDistance = referenceDistance;
  m_referenceLoss = referenceLoss;
}
double
LogDistancePropagationLossModel::GetPathLossExponent (void) const
{
  return m_exponent;
}

double
LogDistancePropagationLossModel::DoCalcRxPower (double txPowerDbm,
                                                Ptr<MobilityModel> a,
                                                Ptr<MobilityModel> b) const

   */
  double pathLossDb = 10 * m_exponent * log10 (distance / m_referenceDistance);
  double rxc = -m_referenceLoss - pathLossDb;
  NS_LOG_DEBUG ("distance=" << distance << "m, reference-attenuation=" << -m_referenceLoss << "dB, " <<
                "attenuation coefficient=" << rxc << "db");
  return txPowerDbm + rxc;
}


                   DoubleValue (46.6777),
                   MakeDoubleAccessor (&ThreeLogDistancePropagationLossModel::m_referenceLoss),
                   MakeDoubleChecker<double> ())
  ;
  return tid;

}

ThreeLogDistancePropagationLossModel::ThreeLogDistancePropagationLossModel ()

                                                     Ptr<MobilityModel> b) const
{
  double distance = a->GetDistanceFrom (b);
  NS_ASSERT (distance >= 0);

  // See doxygen comments for the formula and explanation


  else if (distance < m_distance1)
    {
      pathLossDb = m_referenceLoss
        + 10 * m_exponent0 * log10 (distance / m_distance0);
    }
  else if (distance < m_distance2)
    {
      pathLossDb = m_referenceLoss
        + 10 * m_exponent0 * log10 (m_distance1 / m_distance0)
        + 10 * m_exponent1 * log10 (distance / m_distance1);
    }
  else
    {
      pathLossDb = m_referenceLoss
        + 10 * m_exponent0 * log10 (m_distance1 / m_distance0)
        + 10 * m_exponent1 * log10 (m_distance2 / m_distance1)
        + 10 * m_exponent2 * log10 (distance / m_distance2);
    }

  NS_LOG_DEBUG ("ThreeLogDistance distance=" << distance << "m, " <<

                   DoubleValue (0.75),
                   MakeDoubleAccessor (&NakagamiPropagationLossModel::m_m2),
                   MakeDoubleChecker<double> ())
  ;
  return tid;

}

NakagamiPropagationLossModel::NakagamiPropagationLossModel ()
{
}

double
NakagamiPropagationLossModel::DoCalcRxPower (double txPowerDbm,
                                             Ptr<MobilityModel> a,
                                             Ptr<MobilityModel> b) const

  // select m parameter

  double distance = a->GetDistanceFrom (b);
  NS_ASSERT (distance >= 0);

  double m;
  if (distance < m_distance1)

    {
      m = m_m2;
    }

  // the current power unit is dBm, but Watt is put into the Nakagami /
  // Rayleigh distribution.
  double powerW = pow (10, (txPowerDbm - 30) / 10);

  double resultPowerW;

  // switch between Erlang- and Gamma distributions: this is only for
  // speed. (Gamma is equal to Erlang for any positive integer m.)
  unsigned int int_m = static_cast<unsigned int> (floor (m));

  if (int_m == m)
    {
      resultPowerW = m_erlangRandomVariable.GetValue (int_m, powerW / m);
    }
  else
    {
      resultPowerW = m_gammaRandomVariable.GetValue (m, powerW / m);
    }

  double resultPowerDbm = 10 * log10 (resultPowerW) + 30;

  NS_LOG_DEBUG ("Nakagami distance=" << distance << "m, " <<
                "power=" << powerW << "W, " <<
                "resultPower=" << resultPowerW << "W=" << resultPowerDbm << "dBm");

  return resultPowerDbm;

                   DoubleValue (-150.0),
                   MakeDoubleAccessor (&FixedRssLossModel::m_rss),
                   MakeDoubleChecker<double> ())
  ;
  return tid;
}
FixedRssLossModel::FixedRssLossModel ()
  : PropagationLossModel ()
{
}

FixedRssLossModel::~FixedRssLossModel ()
{
}

void
FixedRssLossModel::SetRss (double rss)
{
  m_rss = rss;
}

double
FixedRssLossModel::DoCalcRxPower (double txPowerDbm,
                                  Ptr<MobilityModel> a,
                                  Ptr<MobilityModel> b) const
{
  return m_rss;
}




 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
 * Contributions: Timo Bingmann <timo.bingmann@student.kit.edu>
 * Contributions: Gary Pei <guangyu.pei@boeing.com> for fixed RSS
 * Contributions: Tom Hewer <tomhewer@mac.com> for porting Two Ray Ground
 */

#ifndef PROPAGATION_LOSS_MODEL_H

  double m_minDistance;
};

/*
 *
 * \brief a Two-Ray Ground propagation loss model ported from NS2
 *
 * Two-ray ground reflection model.
 *
 * \f$ Pr = \frac{Pt * Gt * Gr * (ht^2 * hr^2)}{d^4 * L} \f$
 *
 * The original equation in Rappaport's book assumes L = 1.
 * To be consistant with the free space equation, L is added here.
 *
 * Ht and Hr are set at the respective nodes z coordinate plus a model parameter
 * set via SetHeightAboveZ.
 *
 * The two-ray model does not give a good result for short distances, due to the
 * oscillation caused by constructive and destructive combination of the two
 * rays. Instead the Friis free-space model is used for small distances. 
 *
 * The crossover distance, below which Friis is used, is calculated as follows:
 *
 * \f$ dCross = \frac{(4 * pi * Ht * Hr)}{lambda} \f$
 */

class TwoRayGroundPropagationLossModel : public PropagationLossModel
{
public:
  static TypeId GetTypeId (void);
  TwoRayGroundPropagationLossModel ();
  /**
   * \param frequency (Hz)
   * \param speed (m/s)
   *
   * Set the main wavelength used in the TwoRayGround model 
   * calculation.
   */
  void SetLambda (double frequency, double speed);
  /**
   * \param lambda (m) the wavelength
   *
   * Set the main wavelength used in the TwoRayGround model 
   * calculation.
   */
  void SetLambda (double lambda);
  /**
   * \param systemLoss (dimension-less)
   *
   * Set the system loss used by the TwoRayGround propagation model.
   */
  void SetSystemLoss (double systemLoss);
  /**
   * \param minDistance the minimum distance
   *
   * Below this distance, the txpower is returned
   * unmodified as the rxpower.
   */
  void SetMinDistance (double minDistance);
  /**
   * \returns the minimum distance.
   */
  double GetMinDistance (void) const;
  /**
   * \returns the current wavelength (m)
   */
  double GetLambda (void) const;
  /**
   * \returns the current system loss (dimention-less)
   */
  double GetSystemLoss (void) const;
  /**
   * \Set the model antenna height above the node's Z coordinate
   */
  void SetHeightAboveZ (double heightAboveZ);

private:
  TwoRayGroundPropagationLossModel (const TwoRayGroundPropagationLossModel &o);
  TwoRayGroundPropagationLossModel & operator = (const TwoRayGroundPropagationLossModel &o);
  virtual double DoCalcRxPower (double txPowerDbm,
                                Ptr<MobilityModel> a,
                                Ptr<MobilityModel> b) const;
  double DbmToW (double dbm) const;
  double DbmFromW (double w) const;

  static const double PI;
  double m_lambda;
  double m_systemLoss;
  double m_minDistance;
  double m_heightAboveZ;
};

/**
 * \brief a log distance propagation model.
 *

  double GetPathLossExponent (void) const;

  void SetReference (double referenceDistance, double referenceLoss);

private:
  LogDistancePropagationLossModel (const LogDistancePropagationLossModel &o);
  LogDistancePropagationLossModel & operator = (const LogDistancePropagationLossModel &o);

 *
 * \f[\displaystyle L =
\begin{cases}
0 & d < d_0 \ \
L_0 + 10 \cdot n_0 \log_{10}(\frac{d}{d_0}) & d_0 \leq d < d_1 \ \
L_0 + 10 \cdot n_0 \log_{10}(\frac{d_1}{d_0}) + 10 \cdot n_1 \log_{10}(\frac{d}{d_1}) & d_1 \leq d < d_2 \ \
L_0 + 10 \cdot n_0 \log_{10}(\frac{d_1}{d_0}) + 10 \cdot n_1 \log_{10}(\frac{d_2}{d_1}) + 10 \cdot n_2 \log_{10}(\frac{d}{d_2})& d_2 \leq d
\end{cases}\f]
 *

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