Diagonalizer.h

/* Copyright 2016 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_DIAGONALIZATION
#define COM_DAFER45_TBTK_SOLVER_DIAGONALIZATION

#include "TBTK/CArray.h"
#include "TBTK/Communicator.h"
#include "TBTK/Model.h"
#include "TBTK/Solver/Solver.h"

#include <complex>

namespace TBTK{
namespace Solver{

class Diagonalizer : public Solver, public Communicator{
public:
    class SelfConsistencyCallback{
    public:
        virtual bool selfConsistencyCallback(Diagonalizer &diagonalizer) = 0;
    };

    Diagonalizer();

    void setSelfConsistencyCallback(
        SelfConsistencyCallback &selfConsistencyCallback
    );

    void setMaxIterations(int maxIterations);

    void run();

    const CArray<double>& getEigenValues();

    CArray<double>& getEigenValuesRW();

    const CArray<std::complex<double>>& getEigenVectors();

    CArray<std::complex<double>>& getEigenVectorsRW();

    const double getEigenValue(int state);

    const std::complex<double> getAmplitude(int state, const Index &index);
private:
    CArray<std::complex<double>> hamiltonian;

    CArray<double> eigenValues;

    CArray<std::complex<double>> eigenVectors;

    CArray<std::complex<double>> basisTransformation;

    int maxIterations;

    SelfConsistencyCallback *selfConsistencyCallback;

    void init();

    void update();

    void solve();

    void setupBasisTransformation();

    void transformToOrthonormalBasis();

    void transformToOriginalBasis();
};

inline void Diagonalizer::setSelfConsistencyCallback(
    SelfConsistencyCallback &selfConsistencyCallback
){
    this->selfConsistencyCallback = &selfConsistencyCallback;
}

inline void Diagonalizer::setMaxIterations(int maxIterations){
    this->maxIterations = maxIterations;
}

inline const CArray<double>& Diagonalizer::getEigenValues(){
    return eigenValues;
}

inline CArray<double>& Diagonalizer::getEigenValuesRW(){
    return eigenValues;
}

inline const CArray<std::complex<double>>& Diagonalizer::getEigenVectors(){
    return eigenVectors;
}

inline CArray<std::complex<double>>& Diagonalizer::getEigenVectorsRW(){
    return eigenVectors;
}

inline const std::complex<double> Diagonalizer::getAmplitude(
    int state,
    const Index &index
){
    const Model &model = getModel();
    return eigenVectors[model.getBasisSize()*state + model.getBasisIndex(index)];
}

inline const double Diagonalizer::getEigenValue(int state){
    return eigenValues[state];
}

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

#endif