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Diffstat (limited to 'src/gensvm_zv.c')
| -rw-r--r-- | src/gensvm_zv.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/src/gensvm_zv.c b/src/gensvm_zv.c new file mode 100644 index 0000000..81a5354 --- /dev/null +++ b/src/gensvm_zv.c @@ -0,0 +1,115 @@ +/** + * @file gensvm_zv.c + * @author Gertjan van den Burg + * @date 2016-10-17 + * @brief Functions for computing the ZV matrix product + * + * @details + * This file exists because the product Z*V of two matrices occurs both in the + * computation of the loss function and for predicting class labels. Moreover, + * a distinction has to be made between dense Z matrices and sparse Z + * matrices, hence a seperate file is warranted. + + * Copyright (C) + + This program 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 2 + of the License, or (at your option) any later version. + + This program 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 this program; if not, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + + */ + +#include "gensvm_zv.h" + +/** + * @brief Wrapper around sparse/dense versions of this function + * + * @details + * This function tests if the data is stored in dense format or sparse format + * by testing if GenData::Z is NULL or not, and calls the corresponding + * version of this function accordingly. + * + * @sa + * gensvm_calculate_ZV_dense(), gensvm_calculate_ZV_sparse() + * + * @param[in] model a GenModel instance holding the model + * @param[in] data a GenData instance with the data + * @param[out] ZV a pre-allocated matrix of appropriate dimensions + */ +void gensvm_calculate_ZV(struct GenModel *model, struct GenData *data, + double *ZV) +{ + if (data->Z == NULL) + gensvm_calculate_ZV_sparse(model, data, ZV); + else + gensvm_calculate_ZV_dense(model, data, ZV); +} + +/** + * @brief Compute the product Z*V for when Z is a sparse matrix + * + * @details + * This is a simple sparse-dense matrix multiplication, which uses + * cblas_daxpy() for each nonzero element of Z, to compute Z*V. + * + * @param[in] model a GenModel instance holding the model + * @param[in] data a GenData instance with the data + * @param[out] ZV a pre-allocated matrix of appropriate dimensions + */ +void gensvm_calculate_ZV_sparse(struct GenModel *model, + struct GenData *data, double *ZV) +{ + long i, j, jj, jj_start, jj_end, K, + n_row = data->spZ->n_row; + double z_ij; + + K = model->K; + + int *Zia = data->spZ->ia; + int *Zja = data->spZ->ja; + double *vals = data->spZ->values; + + for (i=0; i<n_row; i++) { + jj_start = Zia[i]; + jj_end = Zia[i+1]; + + for (jj=jj_start; jj<jj_end; jj++) { + j = Zja[jj]; + z_ij = vals[jj]; + + cblas_daxpy(K-1, z_ij, &model->V[j*(K-1)], 1, + &ZV[i*(K-1)], 1); + } + } +} + +/** + * @brief Compute the product Z*V for when Z is a dense matrix + * + * @details + * This function uses cblas_dgemm() to compute the matrix product between Z + * and V. + * + * @param[in] model a GenModel instance holding the model + * @param[in] data a GenData instance with the data + * @param[out] ZV a pre-allocated matrix of appropriate dimensions + */ +void gensvm_calculate_ZV_dense(struct GenModel *model, + struct GenData *data, double *ZV) +{ + long n = model->n; + long m = model->m; + long K = model->K; + + cblas_dgemm(CblasRowMajor, CblasNoTrans, CblasNoTrans, n, K-1, m+1, + 1.0, data->Z, m+1, model->V, K-1, 0, ZV, K-1); +} |