hamsparse.h

/* Copyright (C) 2012-2014  Ward Poelmans

This file is part of Hubbard-GPU.

Hubbard-GPU is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Hubbard-GPU 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with Hubbard-GPU.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef HAMSPARSE_H
#define HAMSPARSE_H

/**
 * Store the Hamiltonian for 1D Hubbard in the (sparse) ELL format
 * @author Ward Poelmans <wpoely86@gmail.com>
 */
template<class Ham>
class SparseHamiltonian: public Ham
{
    public:
	SparseHamiltonian(int L, int Nu, int Nd, double J, double U);
	virtual ~SparseHamiltonian();

        void BuildHam();

	void BuildSparseHam();

	void PrintSparse() const;

	void PrintRawELL() const;

        virtual void mvprod(double *, double *, double) const;

        double* Umatrix() const;

    protected:

	//! The array to hold the data (ELL format) for the up hamiltonian
	double *Up_data;
	//! The array to hold the data (ELL format) for the down hamiltonian
	double *Down_data;

	//! The array to hold the indices for the up hamiltonian
	unsigned int *Up_ind;
	//! The array to hold the indices for the down hamiltonian
	unsigned int *Down_ind;

	//! Maximum number of non zero elements in a row for the up hamiltonian
	int size_Up;
	//! Maximum number of non zero elements in a row for the down hamiltonian
	int size_Down;

};

#endif /* HAMSPARSE_H */

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