std::vector<typename MAT::type>
cal_det_as_vector(const O& creation_operators, const O& annihilation_operators, MAT& M, double BETA, const G& F) {
typedef typename MAT::type SCALAR;
const int size1 = creation_operators.size();
if (size1 == 0) {
throw std::runtime_error("size is zero in cal_det_as_vector");
}
assert(creation_operators.size() == annihilation_operators.size());
Eigen::Matrix<SCALAR, Eigen::Dynamic, Eigen::Dynamic> matrix(size1, size1);
construct_blas_matrix(matrix, creation_operators, annihilation_operators, BETA, F);
Eigen::FullPivLU<Eigen::Matrix<SCALAR, Eigen::Dynamic, Eigen::Dynamic> > lu(matrix);
std::vector<SCALAR> results(size1);
for (int i = 0; i < size1; ++i) {
results[i] = lu.matrixLU()(i,i);
}
results[0] *= lu.permutationP().determinant()*lu.permutationQ().determinant();
M.destructive_resize(size1, size1);
if (size1 > 0) {
M.block() = matrix;
M.safe_invert();
}
return results;
}
typename MAT::type
det_rat_row_column_up(int flavor_ins, int flavor_rem, double t_ins, double t_rem, int row, int column, const MAT & M,
const operator_container_t& creation_operators, const operator_container_t& annihilation_operators, const HYB& F, MAT2& sign_Fs, MAT2& Fe_M, double BETA) {
typedef typename MAT::type SCALAR;
const double sign=((row+column)%2==0 ? 1 : -1);
if (annihilation_operators.size()>0) {
operator_container_t::iterator it_c=creation_operators.begin();
operator_container_t::iterator it_a=annihilation_operators.begin();
Eigen::Matrix<SCALAR,Eigen::Dynamic,Eigen::Dynamic> Fe(1,annihilation_operators.size());
if (annihilation_operators.size()!=creation_operators.size()) {
throw std::runtime_error("annihilation_operators.size()!=creation_operators.size() in det_rat_row_column_up");
}
for (int i=0; i<(int)creation_operators.size(); i++) {
Fe(0,i) = interpolate_F(t_rem-it_c->time(), BETA, F[flavor_rem][it_c->flavor()]);
sign_Fs(i,0) = sign*interpolate_F(it_a->time()-t_ins, BETA, F[(int)(it_a->flavor())][flavor_ins]);
it_c++;
it_a++;
}
Fe_M = Fe*M.block();
return sign*interpolate_F(t_rem-t_ins, BETA, F[flavor_rem][flavor_ins])-(Fe_M*sign_Fs)(0,0);
} else {
return sign*interpolate_F(t_rem-t_ins, BETA, F[flavor_rem][flavor_ins]);
}
}
RET
cal_det(const O& creation_operators, const O& annihilation_operators, MAT& M, double BETA, const G& F) {
typedef typename MAT::type SCALAR;
const int size1 = creation_operators.size();
if (size1==0) return RET(1.0);
assert(creation_operators.size()==annihilation_operators.size());
Eigen::Matrix<SCALAR,Eigen::Dynamic,Eigen::Dynamic> matrix(size1,size1);
construct_blas_matrix(matrix, creation_operators, annihilation_operators, BETA, F);
RET det = safe_determinant<RET>(matrix);
M.destructive_resize(size1,size1);
if (size1>0) {
M.block() = matrix;
M.safe_invert();
}
return det;
}
void compute_M_row_column_up(int row, int column, MAT & M, MAT2& sign_Fs, MAT2& Fe_M, typename MAT::type det_rat) {
typedef typename MAT::type SCALAR;
SCALAR det_rat_inv=1./det_rat;
double sign=((row+column)%2==0 ? 1 : -1);
Eigen::Matrix<SCALAR,Eigen::Dynamic,Eigen::Dynamic> M_sign_Fs(sign_Fs.size(),1);
M_sign_Fs = M.block()*sign_Fs;
assert(M.size1()==M.size2());
MAT M_new(M.size1()+1,M.size2()+1);
int i_new;
int j_new;
// element (j,i)
M_new(column,row) = sign*det_rat_inv;
// row j and column i
for (int k=0; k<M.size1(); k++) {
i_new = (k<column ? k : k+1);
j_new = (k<row ? k : k+1);
M_new(i_new,row) = -M_sign_Fs(k)*det_rat_inv;
M_new(column,j_new) = -sign*Fe_M(k)*det_rat_inv;
}
// remaining elements
for (int k=0; k<M.size1(); k++) {
i_new = (k<column ? k : k+1);
for (int l=0; l<M.size1(); l++) {
j_new = (l<row ? l : l+1);
M_new(i_new, j_new) = M(k,l) + M_sign_Fs(k)*Fe_M(l)*det_rat_inv;
}
}
M_new.swap(M);
return;
}
