#line 1 "/user/cvsspst/ees1cg/RAVL/RAVL-0.7/PatternRec/Distance/DistanceMahalanobis.hh"
// This file is part of RAVL, Recognition And Vision Library 
// Copyright (C) 2001, University of Surrey
// This code may be redistributed under the terms of the GNU Lesser
// General Public License (LGPL). See the lgpl.licence file for details or
// see http://www.gnu.org/copyleft/lesser.html
// file-header-ends-here
#ifndef RAVL_DISTANCEMAHALANOBIS_HEADER 
#define RAVL_DISTANCEMAHALANOBIS_HEADER 1
//////////////////////////////////////////////////////////////
//! rcsid="$Id: DistanceMahalanobis.hh,v 1.6 2002/06/19 19:18:53 craftit Exp $"
//! lib=RavlPatternRec
//! docentry="Ravl.Pattern Recognition.Distance"
//! file="Ravl/PatternRec/Distance/DistanceMahalanobis.hh"

#include "Ravl/PatternRec/Distance.hh"
#include "Ravl/Matrix.hh"

namespace RavlN {
  
  //! userlevel=Develop
  //: Mahalanobis Distance body.
  
  class DistanceMahalanobisBodyC
    : public DistanceBodyC
  {
  public:
    DistanceMahalanobisBodyC(const MatrixC &covVar);
    //: Constructor.
    
    DistanceMahalanobisBodyC(istream &strm);
    //: Load from stream.
    
    DistanceMahalanobisBodyC(BinIStreamC &strm);
    //: Load from binary stream.
    
    virtual bool Save (ostream &out) const;
    //: Writes object to stream, can be loaded using constructor
    
    virtual bool Save (BinOStreamC &out) const;
    //: Writes object to stream, can be loaded using constructor
    
    virtual RealT Measure(const VectorC &d1,const VectorC &d2) const;
    //: Measure the distance from d1 to d2.
    
    virtual RealT Magnitude(const VectorC &d1) const;
    //: Measure the magnitude of d1.

    virtual MatrixC Jacobian (const VectorC &X) const;
    //: Calculates Jacobian matrix at X
    
  protected:
    MatrixC iCovar; // Inverse covariance matrix.
  };
  
  //! userlevel=Normal
  //: Mahalanobis distance metric
  
  class DistanceMahalanobisC
    : public DistanceC
  {
  public:
    DistanceMahalanobisC(const MatrixC &covVar)
      : DistanceC(*new DistanceMahalanobisBodyC(covVar))
    {}
    //: Default constructor.
    
    DistanceMahalanobisC(istream &strm);
    //: Load from stream.
    
    DistanceMahalanobisC(BinIStreamC &strm);
    //: Load from binary stream.
    
  };
  
  inline istream &operator>>(istream &strm,DistanceMahalanobisC &obj) {
    obj = DistanceMahalanobisC(strm);
    return strm;
  }
  //: Load from a stream.
  // Uses virtual constructor.
  
  inline ostream &operator<<(ostream &out,const DistanceMahalanobisC &obj) {
    obj.Save(out);
    return out;
  }
  //: Save to a stream.
  // Uses virtual constructor.
  
  inline BinIStreamC &operator>>(BinIStreamC &strm,DistanceMahalanobisC &obj) {
    obj = DistanceMahalanobisC(strm);
    return strm;
  }
  //: Load from a binary stream.
  // Uses virtual constructor.
  
  inline BinOStreamC &operator<<(BinOStreamC &out,const DistanceMahalanobisC &obj) {
    obj.Save(out);
    return out;
  }
  //: Save to a stream.
  // Uses virtual constructor.


}



#endif