InteractionAmplitude.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_INTERACTION_AMPLITUDE
#define COM_DAFER45_TBTK_INTERACTION_AMPLITUDE
 
#include "TBTK/Index.h"
 
#include <complex>
#include <initializer_list>
 
namespace TBTK{
 
class InteractionAmplitude{
public:
    InteractionAmplitude();
 
    InteractionAmplitude(
        std::complex<double> amplitude,
        std::initializer_list<Index> creationOperatorIndices,
        std::initializer_list<Index> annihilationOperatorIndices
    );
 
    InteractionAmplitude(
        std::complex<double> (*amplitudeCallback)(const std::vector<Index>&, const std::vector<Index>&),
        std::initializer_list<Index> toIndex,
        std::initializer_list<Index> fromIndex
    );
 
    InteractionAmplitude(const InteractionAmplitude &ia);
 
    ~InteractionAmplitude();
 
    std::complex<double> getAmplitude() const;
 
    unsigned int getNumCreationOperators() const;
 
    unsigned int getNumAnnihilationOperators() const;
 
    const Index& getCreationOperatorIndex(unsigned int n) const;
 
    const Index& getAnnihilationOperatorIndex(unsigned int n) const;
private:
    std::complex<double> amplitude;
 
    std::complex<double> (*amplitudeCallback)(
        const std::vector<Index> &toIndex,
        const std::vector<Index> &fromIndex
    );
 
    std::vector<Index> creationOperatorIndices;
 
    std::vector<Index> annihilationOperatorIndices;
};
 
inline std::complex<double> InteractionAmplitude::getAmplitude() const{
    if(amplitudeCallback)
        return amplitudeCallback(creationOperatorIndices, annihilationOperatorIndices);
    else
        return amplitude;
}
 
inline unsigned int InteractionAmplitude::getNumCreationOperators() const{
    return creationOperatorIndices.size();
}
 
inline unsigned int InteractionAmplitude::getNumAnnihilationOperators() const{
    return annihilationOperatorIndices.size();
}
 
inline const Index& InteractionAmplitude::getCreationOperatorIndex(unsigned int n) const{
    return creationOperatorIndices.at(n);
}
 
inline const Index& InteractionAmplitude::getAnnihilationOperatorIndex(unsigned int n) const{
    return annihilationOperatorIndices.at(n);
}
 
};  //End of namespace TBTK
 
#endif