AnalyticalContinuerContinuousFractions.h

/* Copyright 2019 Kristofer Björnson
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */


#ifndef COM_DAFER45_TBTK_SOLVER_ANALYTICAL_CONTINUER_CONTINUOUS_FRACTIONS
#define COM_DAFER45_TBTK_SOLVER_ANALYTICAL_CONTINUER_CONTINUOUS_FRACTIONS

#include "TBTK/Communicator.h"
#include "TBTK/Property/GreensFunction.h"
#include "TBTK/Property/SelfEnergy.h"
#include "TBTK/Solver/Solver.h"

#include <complex>

namespace TBTK{
namespace Solver{

class AnalyticalContinuerContinuousFractions : public Solver, public Communicator{
public:
    AnalyticalContinuerContinuousFractions();

    void setEnergyWindow(
        double lowerBound,
        double upperBound,
        int resolution
    );

    void setEnergyInfinitesimal(double energyInfinitesimal);

    Property::GreensFunction convert(
        const Property::GreensFunction &greensFunction,
        Property::GreensFunction::Type type
    ) const;
private:
    double lowerBound;

    double upperBound;

    int resolution;

    static constexpr double ENERGY_INFINITESIMAL = 0;

    double energyInfinitesimal;

    std::complex<double> getContourDeformation(
        double energy,
        Property::GreensFunction::Type type
    ) const;
};

inline void AnalyticalContinuerContinuousFractions::setEnergyWindow(
    double lowerBound,
    double upperBound,
    int resolution
){
    this->lowerBound = lowerBound;
    this->upperBound = upperBound;
    this->resolution = resolution;
}

inline void AnalyticalContinuerContinuousFractions::setEnergyInfinitesimal(
    double energyInfinitesimal
){
    this->energyInfinitesimal = energyInfinitesimal;
}

};  //End of namespace Solver
};  //End of namespace TBTK

#endif