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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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8
Eigen/src/SparseCore/ConservativeSparseSparseProduct.h
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@@ -30,16 +30,16 @@ static void conservative_sparse_sparse_product_impl(const Lhs& lhs, const Rhs& r
std::memset(mask,0,sizeof(bool)*rows);
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 = lhs.nonZeros() + rhs.nonZeros();
typename evaluator<Lhs>::type lhsEval(lhs);
typename evaluator<Rhs>::type rhsEval(rhs);
Index estimated_nnz_prod = lhsEval.nonZerosEstimate() + rhsEval.nonZerosEstimate();
res.setZero();
res.reserve(Index(estimated_nnz_prod));