JFIT::JMEstimatorTukey Struct Reference

Tukey's biweight M-estimator. More...

#include <JMEstimator.hh>

Inheritance diagram for JFIT::JMEstimatorTukey:

Public Member Functions
	JMEstimatorTukey (const double k)
	Constructor.
virtual double	getRho (const double z) const override
	Get maximum likelihood estimate.
virtual double	getPsi (const double z) const override
	Get derivative of maximum likelihood estimate.

Public Attributes
double	k

Detailed Description

Tukey's biweight M-estimator.

This estimator produces a redescending dependence for large deviations.

Definition at line 108 of file JMEstimator.hh.

Constructor & Destructor Documentation

JMEstimatorTukey()

JFIT::JMEstimatorTukey::JMEstimatorTukey ( const double k )

inline

Constructor.

Parameters

k	standard deviation

Definition at line 116 of file JMEstimator.hh.

                                     :
      k(k)
    {}

Member Function Documentation

getRho()

virtual double JFIT::JMEstimatorTukey::getRho ( const double z ) const

inlineoverridevirtual

Get maximum likelihood estimate.

Parameters

z

deviation

Returns

likelihood

Implements JFIT::JMEstimator.

Definition at line 120 of file JMEstimator.hh.

    { 
      const double w = 0.5 * k*k / 3.0;
 
      if (fabs(z) < k) {
 
        const double u = z/k;
        const double v = 1.0 - u*u;
        
        return w * (1.0 - v*v*v);
      }
 
      return w;
    }

getPsi()

virtual double JFIT::JMEstimatorTukey::getPsi ( const double z ) const

inlineoverridevirtual

Get derivative of maximum likelihood estimate.

Parameters

z

deviation

Returns

derivative

Implements JFIT::JMEstimator.

Definition at line 135 of file JMEstimator.hh.

    { 
      if (fabs(z) < k) {
 
        const double u = z/k;
        const double v = 1.0 - u*u;
        
        return z * v*v;
      }
 
      return 0.0;
    }

Member Data Documentation

k

double JFIT::JMEstimatorTukey::k

Definition at line 148 of file JMEstimator.hh.

---

The documentation for this struct was generated from the following file:

• JMEstimator.hh