src/lib/chemistry/qc/mbptr12/gaussianfit.h

//
// gaussianfit.h
//
// Copyright (C) 2007 Edward Valeev
//
// Author: Edward Valeev <evaleev@vt.edu>
// Maintainer: EV
//
// This file is part of the SC Toolkit.
//
// The SC Toolkit is free software; you can redistribute it and/or modify
// it under the terms of the GNU Library General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
//
// The SC Toolkit is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public License
// along with the SC Toolkit; see the file COPYING.LIB.  If not, write to
// the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
//
// The U.S. Government is granted a limited license as per AL 91-7.
//

#ifdef __GNUC__
#pragma interface
#endif

#include <stdexcept>
#include <vector>
#include <cmath>

#ifndef _chemistry_qc_mbptr12_gaussianfit_h
#define _chemistry_qc_mbptr12_gaussianfit_h

namespace sc {

    template <typename Function,
              typename Weight>
    class GaussianFit {
    public:
        // If 1, "weigh" the function, else weigh the square of the error
        static const bool weigh_F = 0;

        typedef double Exp;
        typedef double Coef;
        typedef std::pair<Exp,Coef> Gaussian;
        typedef std::vector<Gaussian> Gaussians;
        GaussianFit(unsigned int N,
                    const Weight& W,
                    double left,
                    double right,
                    unsigned int NP);
        ~GaussianFit();

        const Gaussians& operator()(const Function& F) const;
        
    private:
        static const int k_ = 0;

        Weight weight_;
        mutable std::vector< std::pair<Exp,Coef> > gaussians_;
        double left_;
        double right_;
        unsigned int npts_;

        mutable double* p_;
        double* scratch_;

        static const int classdebug_ = 0;

        void extract_params() const;
        void assign_params() const;
    };

    namespace mbptr12 {
        class Slater1D {
        public:
            Slater1D(double a, int k=0) : a_(a), k_(k) {}
            double operator()(double x) const { return std::pow(x,k_) * std::exp(-a_*x); }
        private:
            int k_;
            double a_;
        };
        class Gaussian1D {
        public:
            Gaussian1D(double a, int k=0) : a_(a), k_(k) {}
            double operator()(double x) const { return std::pow(x,k_) * std::exp(-a_*x*x); }
        private:
            int k_;
            double a_;
        };
        class PowerGaussian1D {
        public:
            PowerGaussian1D(double a, int l=2, int k=0) : a_(a), k_(k), l_(l) {}
            double operator()(double x) const { return std::pow(x,k_) * std::exp(-a_*std::pow(x,l_)); }
        private:
            int k_;
            int l_;
            double a_;
        };
    }

}
  
#endif

// Local Variables:
// mode: c++
// c-file-style: "ETS"
// End:

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