/*! \file lib/resol_targetfn.h
    Header file for resolution function generator
*/
//C Copyright (C) 2000-2006 Kevin Cowtan and University of York
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#ifndef CLIPPER_RESOL_TARGETFN
#define CLIPPER_RESOL_TARGETFN

#include "resol_basisfn.h"
#include "hkl_datatypes.h"


namespace clipper {


  //! simple mean |F|<sup>n</sup> target
  /*! This class implements the target function for calculating mean
    |F|<sup>n</sup> as a function of position in reciprocal space. It
    includes the appropriate multiplicity correction, and so can be
    applied to any type with an 'f' member with the same dimensions as
    an |F| or |U| (or an uncorrected |E|).

    \Note This function should not be used to scale F's to E's.
    See TargetFn_scaleEsq. */
  template<class T> class TargetFn_meanFnth : public TargetFn_base
  {
  public:
    //! constructor: takes the datalist against which to calc target, and power
    TargetFn_meanFnth( const HKL_data<T>& hkl_data_, const ftype& n );
    //! return the value and derivatives of the target function
    Rderiv rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const;
    //! the type of the function: optionally used to improve convergence
    FNtype type() const { return QUADRATIC; }
  private:
    ftype power;
    const HKL_data<T>* hkl_data;
  };


  //! simple mean |E|<sup>n</sup> target
  /*! This class implements the target function for calculating mean
    |E|<sup>n</sup> as a function of position in reciprocal space. It
    includes the appropriate multiplicity correction, and so can be
    applied to any type with an 'E' member with the same dimensions as
    an |E| (or corrected |F| or |U|).

    \Note This function should not be used to scale F's to E's.
    See TargetFn_scaleEsq. */
  template<class T> class TargetFn_meanEnth : public TargetFn_base
  {
  public:
    //! constructor: takes the datalist against which to calc target, and power
    TargetFn_meanEnth( const HKL_data<T>& hkl_data_, const ftype& n );
    //! return the value and derivatives of the target function
    Rderiv rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const;
    //! the type of the function: optionally used to improve convergence
    FNtype type() const { return QUADRATIC; }
  private:
    ftype power;
    const HKL_data<T>* hkl_data;
  };


  //! |F|<sup>2</sup> scaling target
  /*! This class implements the target function for calculating the
    scale factor to scale one set of F's to another. The resulting
    scale is the square of the factor that scales the first set of
    data to match the second. */
  template<class T1, class T2> class TargetFn_scaleF1F2 : public TargetFn_base
  {
  public:
    //! constructor: takes the datalist against which to calc target
    TargetFn_scaleF1F2( const HKL_data<T1>& hkl_data1_, const HKL_data<T2>& hkl_data2_ );
    //! return the value and derivatives of the target function
    Rderiv rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const;
    //! the type of the function: optionally used to improve convergence
    FNtype type() const { return QUADRATIC; }
  private:
    const HKL_data<T1>* hkl_data1;
    const HKL_data<T2>* hkl_data2;
  };


  //! log |F|<sup>2</sup> scaling target
  /*! This class implements the target function for calculating the
    scale factor to scale the weighted log of one set of F's to
    another. The resulting scale is the square of the factor that
    scales the first set of data to match the second. The log scaling
    target is used in conjunction with the log-Gaussian basis
    functions for a fast and robust approximation to iso/aniso
    Gaussian scaling.
  */
  template<class T1, class T2> class TargetFn_scaleLogF1F2 : public TargetFn_base
  {
  public:
    //! constructor: takes the datalist against which to calc target
    TargetFn_scaleLogF1F2( const HKL_data<T1>& hkl_data1_, const HKL_data<T2>& hkl_data2_ );
    //! return the value and derivatives of the target function
    Rderiv rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const;
    //! the type of the function: optionally used to improve convergence
    FNtype type() const { return QUADRATIC; }
  private:
    const HKL_data<T1>* hkl_data1;
    const HKL_data<T2>* hkl_data2;
  };


  //! |E|<sup>2</sup> scaling target
  /*! This class implements the target function for calculating the
    scale factor to normalise to <|E|<sup>2</sup>> = 1. Note that this
    is not the same as dividing by <|E|<sup>2</sup>>, except in a few
    special cases, e.g. a simple resolution bins calculation. The
    resulting targen function is the square of the value by which |E|
    should be multiplied to acheive the correct normalisation. */
  template<class T> class TargetFn_scaleEsq : public TargetFn_base
  {
  public:
    //! constructor: takes the datalist against which to calc target
    TargetFn_scaleEsq( const HKL_data<T>& hkl_data_ );
    //! return the value and derivatives of the target function
    Rderiv rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const;
    //! the type of the function: optionally used to improve convergence
    FNtype type() const { return QUADRATIC; }
  private:
    const HKL_data<T>* hkl_data;
  };


  //! \deprecated simple sigma_a target function
  /*! This class implements the target function for calculating sigma_a.
    Required is a datalist containing Eo, Ec.

    It actually refines omegaa = sigmaa/(1-sigmaa^2). This has better
    proerties for refinement. To get sigmaa use
    \code sigmaa = ( sqrt( 4*omegaa^2 + 1 ) - 1 ) / ( 2*omegaa ) \endcode
    This is available as a static function:
    \code sigmaa = targetfn.sigmaa( omegaa ) \endcode

    This version simplifies terms in |Eo|^2 and |Ec|^2 which should
    average out to 1 if the normalisation scheme is consistent with
    the sigmaa calc.

    Convergence is good for calculations using the 'binner' basis
    function, however the smooth basis function have convergence
    problems. This is still under investigation.
  */
  template<class T> class TargetFn_sigmaa_omegaa : public TargetFn_base
  {
  public:
    //! constructor: takes the datalist against which to calc target
    TargetFn_sigmaa_omegaa( const HKL_data<T>& eo, const HKL_data<T>& ec );
    //! return the value and derivatives of the target function
    Rderiv rderiv( const HKL_info::HKL_reference_index& ih, const ftype& omegaa ) const;
    //! convert omegaa to sigmaa
    static ftype sigmaa( const ftype& omegaa )
    {
      ftype omeg = (omegaa>0.05) ? omegaa : (0.05*exp(omegaa/0.05-1.0));
      return 0.5 * ( sqrt( 4.0*omeg*omeg + 1.0 ) - 1.0 ) / omeg;
    }
  private:
    const HKL_data<T>* eo_data;
    const HKL_data<T>* ec_data;
  };


  //! \deprecated simple sigma_a target function
  /*! \par Warning: Convergence of this basis-function can be
    unreliable under some circumstances. Use
    clipper::TargetFn_sigmaa_omegaa instead, except for development
    purposes.

    This class implements the target function for calculating sigma_a.
    Required is a datalist containing Eo, Ec.

    This version simplifies terms in |Eo|^2 and |Ec|^2 which should
    average out to 1 if the normalisation scheme is consistent with
    the sigmaa calc.
  */
  template<class T> class TargetFn_sigmaa : public TargetFn_base
  {
  public:
    //! constructor: takes the datalist against which to calc target
    TargetFn_sigmaa( const HKL_data<T>& eo, const HKL_data<T>& ec );
    //! return the value and derivatives of the target function
    Rderiv rderiv( const HKL_info::HKL_reference_index& ih, const ftype& sigmaa0 ) const;
    //! convert function to sigmaa
    static ftype sigmaa( const ftype& sigm ) { return sigm; }
  private:
    const HKL_data<T>* eo_data;
    const HKL_data<T>* ec_data;
  };



  // implementations for template functions

  // mean F^nth

  template<class T> TargetFn_meanFnth<T>::TargetFn_meanFnth( const HKL_data<T>& hkl_data_, const ftype& n )
  {
    power = n;
    hkl_data = &hkl_data_;
  }

  template<class T> TargetFn_base::Rderiv TargetFn_meanFnth<T>::rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const
  {
    Rderiv result;
    const HKL_data<T>& data = *hkl_data;
    if ( !data[ih].missing() ) {
      ftype d = fh - pow( ftype(data[ih].f()) / sqrt(ih.hkl_class().epsilon()),
			  power );
      result.r = d * d;
      result.dr = 2.0 * d;
      result.dr2 = 2.0;
    } else {
      result.r = result.dr = result.dr2 = 0.0;
    }
    return result;
  }

  // mean E^nth

  template<class T> TargetFn_meanEnth<T>::TargetFn_meanEnth( const HKL_data<T>& hkl_data_, const ftype& n )
  {
    power = n;
    hkl_data = &hkl_data_;
  }

  template<class T> TargetFn_base::Rderiv TargetFn_meanEnth<T>::rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const
  {
    Rderiv result;
    const HKL_data<T>& data = *hkl_data;
    if ( !data[ih].missing() ) {
      ftype d = fh - pow( ftype(data[ih].E()), power );
      result.r = d * d;
      result.dr = 2.0 * d;
      result.dr2 = 2.0;
    } else {
      result.r = result.dr = result.dr2 = 0.0;
    }
    return result;
  }

  // F1-F2 scaling

  template<class T1, class T2> TargetFn_scaleF1F2<T1,T2>::TargetFn_scaleF1F2( const HKL_data<T1>& hkl_data1_, const HKL_data<T2>& hkl_data2_ )
  {
    hkl_data1 = &hkl_data1_;
    hkl_data2 = &hkl_data2_;
  }

  template<class T1, class T2> TargetFn_base::Rderiv TargetFn_scaleF1F2<T1,T2>::rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const
  {
    Rderiv result;
    const T1& ft1 = (*hkl_data1)[ih];
    const T2& ft2 = (*hkl_data2)[ih];
    if ( !ft1.missing() && !ft2.missing() ) {
      const ftype eps = ih.hkl_class().epsilon();
      const ftype f1 = pow( ft1.f(), 2 ) / eps;
      const ftype f2 = pow( ft2.f(), 2 ) / eps;
      const ftype d = fh*f1 - f2;
      result.r = d * d / f1;
      result.dr = 2.0 * d;
      result.dr2 = 2.0 * f1;
    } else {
      result.r = result.dr = result.dr2 = 0.0;
    }
    return result;
  }

  // Log F1-F2 scaling

  template<class T1, class T2> TargetFn_scaleLogF1F2<T1,T2>::TargetFn_scaleLogF1F2( const HKL_data<T1>& hkl_data1_, const HKL_data<T2>& hkl_data2_ )
  {
    hkl_data1 = &hkl_data1_;
    hkl_data2 = &hkl_data2_;
  }

  template<class T1, class T2> TargetFn_base::Rderiv TargetFn_scaleLogF1F2<T1,T2>::rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const
  {
    Rderiv result;
    result.r = result.dr = result.dr2 = 0.0;
    const T1& ft1 = (*hkl_data1)[ih];
    const T2& ft2 = (*hkl_data2)[ih];
    if ( !ft1.missing() && !ft2.missing() )
      if ( ft1.f() > 1.0e-6 && ft2.f() > 1.0e-6 ) {
	const ftype eps = ih.hkl_class().epsilon();
	const ftype f1 = pow( ft1.f(), 2 ) / eps;
	const ftype f2 = pow( ft2.f(), 2 ) / eps;
	const ftype w = 1.0;  // f1 * f2;
	const ftype d = fh + log(f1) - log(f2);
	result.r   =       w * d * d;
	result.dr  = 2.0 * w * d;
	result.dr2 = 2.0 * w;
    }
    return result;
  }

  // E^2 scaling

  template<class T> TargetFn_scaleEsq<T>::TargetFn_scaleEsq( const HKL_data<T>& hkl_data_ )
  {
    hkl_data = &hkl_data_;
  }

  template<class T> TargetFn_base::Rderiv TargetFn_scaleEsq<T>::rderiv( const HKL_info::HKL_reference_index& ih, const ftype& fh ) const
  {
    Rderiv result;
    const HKL_data<T>& data = *hkl_data;
    const ftype two(2.0);
    if ( !data[ih].missing() ) {
      ftype fsq = pow( ftype(data[ih].E()), two );
      ftype d = fsq * fh - 1.0;
      result.r = d * d / fsq;
      result.dr = two * d;
      result.dr2 = two * fsq;
    } else {
      result.r = result.dr = result.dr2 = 0.0;
    }
    return result;
  }


  // sigmaa (omegaa)

  template<class T> TargetFn_sigmaa_omegaa<T>::TargetFn_sigmaa_omegaa( const HKL_data<T>& eo, const HKL_data<T>& ec )
  {
    eo_data = &eo;
    ec_data = &ec;
  }

  template<class T> TargetFn_base::Rderiv TargetFn_sigmaa_omegaa<T>::rderiv( const HKL_info::HKL_reference_index& ih, const ftype& omegaa ) const
  {
    Rderiv result;
    
    const HKL_data<T>& eodata = *eo_data;
    const HKL_data<T>& ecdata = *ec_data;
    if ( eodata[ih].missing() || ecdata[ih].missing()  ) {
      result.r = result.dr = result.dr2 = 0.0;
    } else {
      ftype eo = eodata[ih].E();
      ftype ec = ecdata[ih].E();
      ftype omeg = (omegaa>0.05) ? omegaa : (0.05*exp(omegaa/0.05-1.0));
      ftype sigmaa = 0.5*(sqrt(4*omeg*omeg+1)-1)/omeg;
      ftype dx = 2.0 * eo * ec;
      ftype x = dx * omeg;
      ftype t0 = 1.0/(1-sigmaa*sigmaa) + 0.5*log((1-sigmaa*sigmaa));
      ftype t1 = sigmaa;
      ftype t2 = pow(1-sigmaa*sigmaa,2)/(1+sigmaa*sigmaa);
      if ( ih.hkl_class().centric() ) {
	result.r = 1.0*t0 - log( cosh( x/2 ) );
	result.dr = 1.0*t1 - dx*0.5*tanh( x/2 );
	result.dr2 = 1.0*t2 - dx*dx*0.25*(1.0 - pow(tanh(x/2),2) );
      } else {
	result.r = 2.0*t0 - Util::sim_integ( x );
	result.dr = 2.0*t1 - dx*Util::sim( x );
	result.dr2 = 2.0*t2 - dx*dx*Util::sim_deriv( x );
      }
      if ( omegaa < 0.05 ) {
	ftype dy = exp( omegaa/0.05 ) / exp( 1.0 );
	ftype dy2 = exp( omegaa/0.05 ) / ( 0.05*exp( 1.0 ) );
	result.dr2 = result.dr*dy2 + result.dr2*dy*dy;
	result.dr = result.dr*dy;
      }
    }
    return result;
  }


  // sigmaa (norm)

  template<class T> TargetFn_sigmaa<T>::TargetFn_sigmaa( const HKL_data<T>& eo, const HKL_data<T>& ec )
  {
    eo_data = &eo;
    ec_data = &ec;
  }

  template<class T> TargetFn_base::Rderiv TargetFn_sigmaa<T>::rderiv( const HKL_info::HKL_reference_index& ih, const ftype& sigmaa0 ) const
  {
    Rderiv result;
    
    const HKL_data<T>& eodata = *eo_data;
    const HKL_data<T>& ecdata = *ec_data;
    if ( eodata[ih].missing() || ecdata[ih].missing()  ) {
      result.r = result.dr = result.dr2 = 0.0;
    } else {
      ftype eo = eodata[ih].E();
      ftype ec = ecdata[ih].E();
      ftype sigmaa = Util::min( Util::max( sigmaa0, 0.01 ), 0.99 );
      ftype dx = 2.0 * eo * ec;
      ftype x = dx * sigmaa/(1-sigmaa*sigmaa);
      ftype t0 = 1.0/(1-sigmaa*sigmaa) + 0.5*log((1-sigmaa*sigmaa));
      ftype t1 = sigmaa;
      ftype t2 = pow(1-sigmaa*sigmaa,2)/(1+sigmaa*sigmaa);
      if ( ih.hkl_class().centric() ) {
	result.r = 1.0*t0 - log( cosh( x/2 ) );
	result.dr = 1.0*t1 - dx*0.5*tanh( x/2 );
	result.dr2 = 1.0*t2 - dx*dx*0.25*(1.0 - pow(tanh(x/2),2) );
      } else {
	result.r = 2.0*t0 - Util::sim_integ( x );
	result.dr = 2.0*t1 - dx*Util::sim( x );
	result.dr2 = 2.0*t2 - dx*dx*Util::sim_deriv( x );
      }
      ftype ds = (1+sigmaa*sigmaa)/pow(1-sigmaa*sigmaa,2);
      ftype ds2 = 2*sigmaa*(3+sigmaa*sigmaa)/pow(1-sigmaa*sigmaa,3);
      result.dr2 = result.dr*ds2 + result.dr2*ds*ds;
      result.dr = result.dr*ds;
    }
    return result;
  }


} // namespace clipper

#endif
