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bug #875: remove broken SparseMatrixBase::nonZeros and introduce a nonZerosEstimate() method to sparse evaluators for internal uses.

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Factorize some code in SparseCompressedBase.
This commit is contained in:
Gael Guennebaud
2015-04-01 22:27:34 +02:00
parent 39dcd01b0a
commit 3105986e71
13 changed files with 90 additions and 59 deletions
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16
Eigen/src/SparseCore/SparseSparseProductWithPruning.h
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@@ -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());