C++ DistMatrix::LockedBuffer方法代码示例

/*
 * Convert an elemental STAR, STAR distributed vector toa  std::vector
 */
int elstar2vec(const El::DistMatrix<El::Complex<double>,El::STAR,El::STAR> &Y, std::vector<double> &vec){

	const El::Complex<double> *Y_ptr = Y.LockedBuffer();
	int sz = vec.size()/2;
	#pragma omp parallel for
	for(int i=0;i<sz; i++){
		vec[2*i] = El::RealPart(Y_ptr[i]);
		vec[2*i+1] = El::ImagPart(Y_ptr[i]);
	}

	return 0;
}

void L1DistanceMatrixTU(El::UpperOrLower uplo,
    direction_t dirA, direction_t dirB, T alpha,
    const El::DistMatrix<T, El::STAR, El::MC> &A,
    const El::DistMatrix<T, El::STAR, El::MR> &B,
    T beta, El::DistMatrix<T> &C) {

    // TODO verify sizes

    const T *a = A.LockedBuffer();
    El::Int ldA = A.LDim();

    const T *b = B.LockedBuffer();
    El::Int ldB = B.LDim();

    T *c = C.Buffer();
    El::Int ldC = C.LDim();

    El::Int d = A.Height();

    /* Not the most efficient way... but mimicking BLAS is too much work! */
    if (dirA == base::COLUMNS && dirB == base::COLUMNS) {
        El::Int n = C.LocalWidth();
        El::Int m = C.LocalHeight();
        for (El::Int j = 0; j < n; j++)
            for(El::Int i =
                    ((uplo == El::UPPER) ? 0 : C.LocalRowOffset(A.GlobalCol(j)));
                i < ((uplo == El::UPPER) ? C.LocalRowOffset(A.GlobalCol(j) + 1) : m); i++) {

                T v = 0.0;
                for (El::Int k = 0; k < d; k++)
                    v += std::abs(b[j * ldB + k] - a[i * ldA + k]);
                c[j * ldC + i] = beta * c[j * ldC + i] + alpha * v;
            }

    }

    // TODO the rest of the cases.
}

int elemental2vec(const El::DistMatrix<El::Complex<double>,El::VC,El::STAR> &Y, std::vector<double> &vec){
	
	assert((Y.DistData().colDist == El::STAR) and (Y.DistData().rowDist == El::VC));

	int data_dof=2;
	int SCAL_EXP = 1;

	//double *pt_array,*pt_perm_array;
	int r,q,ll,rq; // el vec info
	int nbigs; //Number of large recv (i.e. recv 1 extra data point)
	int pstart; // p_id of nstart
	int rank = El::mpi::WorldRank(); //p_id
	int recv_size; // base recv size
	bool print = (rank == -1); 

	// Get el vec info
	ll = Y.Height();
	const El::Grid* g = &(Y.Grid());
	r = g->Height();
	q = g->Width();
	MPI_Comm comm = (g->Comm()).comm;

	int cheb_deg = InvMedTree<FMM_Mat_t>::cheb_deg;
	int omp_p=omp_get_max_threads();
	size_t n_coeff3=(cheb_deg+1)*(cheb_deg+2)*(cheb_deg+3)/6;
	
	// Get petsc vec params
	//VecGetLocalSize(pt_vec,&nlocal);
	int nlocal = (vec.size())/data_dof;
	if(print) std::cout << "m: " << std::endl;
	int nstart = 0;
	//VecGetArray(pt_vec,&pt_array);
	//VecGetOwnershipRange(pt_vec,&nstart,NULL);
	MPI_Exscan(&nlocal,&nstart,1,MPI_INT,MPI_SUM,comm);

	// Determine who owns the first element we want
	rq = r * q;
	pstart = nstart % rq;
	nbigs = nlocal % rq;
	recv_size = nlocal / rq;
	
	if(print){
		std::cout << "r: " << r << " q: " << q <<std::endl;
		std::cout << "nstart: " << nstart << std::endl;
		std::cout << "ps: " << pstart << std::endl;
		std::cout << "nbigs: " << nbigs << std::endl;
		std::cout << "recv_size: " << recv_size << std::endl;
	}

	// Make recv sizes
	std::vector<int> recv_lengths(rq);
	std::fill(recv_lengths.begin(),recv_lengths.end(),recv_size);
	if(nbigs >0){
		for(int i=0;i<nbigs;i++){
			recv_lengths[(pstart + i) % rq] += 1;
		}
	}

	// Make recv disps
	std::vector<int> recv_disps = exscan(recv_lengths);

	// All2all to get send sizes
	std::vector<int> send_lengths(rq);
	MPI_Alltoall(&recv_lengths[0], 1, MPI_INT, &send_lengths[0], 1, MPI_INT,comm);

	// Scan to get send_disps
	std::vector<int> send_disps = exscan(send_lengths);

	// Do all2allv to get data on correct processor
	std::vector<El::Complex<double>> recv_data(nlocal);
	std::vector<El::Complex<double>> recv_data_ordered(nlocal);
	//MPI_Alltoallv(el_vec.Buffer(),&send_lengths[0],&send_disps[0],MPI_DOUBLE, \
			&recv_data[0],&recv_lengths[0],&recv_disps[0],MPI_DOUBLE,comm);
	El::mpi::AllToAll(Y.LockedBuffer(), &send_lengths[0], &send_disps[0], &recv_data[0],&recv_lengths[0],&recv_disps[0],comm);
	
	if(print){
		//std::cout << "Send data: " <<std::endl << *el_vec.Buffer() <<std::endl;
		std::cout << "Send lengths: " <<std::endl << send_lengths <<std::endl;
		std::cout << "Send disps: " <<std::endl << send_disps <<std::endl;
		std::cout << "Recv data: " <<std::endl << recv_data <<std::endl;
		std::cout << "Recv lengths: " <<std::endl << recv_lengths <<std::endl;
		std::cout << "Recv disps: " <<std::endl << recv_disps <<std::endl;
	}
	
	// Reorder the data so taht it is in the right order for the fmm tree
	for(int p=0;p<rq;p++){
		int base_idx = (p - pstart + rq) % rq;
		int offset = recv_disps[p];
		for(int i=0;i<recv_lengths[p];i++){
			recv_data_ordered[base_idx + rq*i] = recv_data[offset + i];
		}
	}

	// loop through and put the data into the vector
	#pragma omp parallel for
	for(int i=0;i<nlocal; i++){
		vec[2*i] = El::RealPart(recv_data_ordered[i]);
		vec[2*i+1] = El::ImagPart(recv_data_ordered[i]);
	}

//.........这里部分代码省略.........