diff options
Diffstat (limited to 'Eigen/src/SparseCore/SparseSparseProductWithPruning.h')
-rw-r--r-- | Eigen/src/SparseCore/SparseSparseProductWithPruning.h | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/Eigen/src/SparseCore/SparseSparseProductWithPruning.h b/Eigen/src/SparseCore/SparseSparseProductWithPruning.h index 3db01bf2d..48050077e 100644 --- a/Eigen/src/SparseCore/SparseSparseProductWithPruning.h +++ b/Eigen/src/SparseCore/SparseSparseProductWithPruning.h @@ -33,14 +33,6 @@ static void sparse_sparse_product_with_pruning_impl(const Lhs& lhs, const Rhs& r // allocate a temporary buffer AmbiVector<Scalar,StorageIndex> tempVector(rows); - // estimate the number of non zero entries - // given a rhs column containing Y non zeros, we assume that the respective Y columns - // of the lhs differs in average of one non zeros, thus the number of non zeros for - // the product of a rhs column with the lhs is X+Y where X is the average number of non zero - // per column of the lhs. - // Therefore, we have nnz(lhs*rhs) = nnz(lhs) + nnz(rhs) - Index estimated_nnz_prod = lhs.nonZeros() + rhs.nonZeros(); - // mimics a resizeByInnerOuter: if(ResultType::IsRowMajor) res.resize(cols, rows); @@ -49,6 +41,14 @@ static void sparse_sparse_product_with_pruning_impl(const Lhs& lhs, const Rhs& r typename evaluator<Lhs>::type lhsEval(lhs); typename evaluator<Rhs>::type rhsEval(rhs); + + // estimate the number of non zero entries + // given a rhs column containing Y non zeros, we assume that the respective Y columns + // of the lhs differs in average of one non zeros, thus the number of non zeros for + // the product of a rhs column with the lhs is X+Y where X is the average number of non zero + // per column of the lhs. + // Therefore, we have nnz(lhs*rhs) = nnz(lhs) + nnz(rhs) + Index estimated_nnz_prod = lhsEval.nonZerosEstimate() + rhsEval.nonZerosEstimate(); res.reserve(estimated_nnz_prod); double ratioColRes = double(estimated_nnz_prod)/double(lhs.rows()*rhs.cols()); |