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generalize the prune function

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This commit is contained in:
Gael Guennebaud 2010-10-28 11:39:31 +02:00
parent 02c8b6af82
commit 1d4e80f09d
1 changed files with 25 additions and 3 deletions
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28
Eigen/src/Sparse/SparseMatrix.h
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@ -333,16 +333,38 @@ class SparseMatrix
/** Suppress all nonzeros which are smaller than \a reference under the tolerence \a epsilon */ /** Suppress all nonzeros which are smaller than \a reference under the tolerence \a epsilon */
void prune(Scalar reference, RealScalar epsilon = NumTraits<RealScalar>::dummy_precision()) void prune(Scalar reference, RealScalar epsilon = NumTraits<RealScalar>::dummy_precision())
{
struct func {
func(Scalar ref, RealScalar eps) : reference(ref), epsilon(eps) {}
inline bool operator() (const Index& row, const Index& col, const Scalar& value) const
{
return !internal::isMuchSmallerThan(value, reference, epsilon);
}
Scalar reference;
RealScalar epsilon;
};
prune(func(reference,epsilon));
}
/** Suppress all nonzeros which do not satisfy the predicate \a keep.
* The functor type \a KeepFunc must implement the following function:
* \code
* bool operator() (const Index& row, const Index& col, const Scalar& value) const;
* \endcode
* \sa prune(Scalar,RealScalar)
*/
template<typename KeepFunc>
void prune(const KeepFunc& keep = KeepFunc())
{ {
Index k = 0; Index k = 0;
for (Index j=0; j<m_outerSize; ++j) for(Index j=0; j<m_outerSize; ++j)
{ {
Index previousStart = m_outerIndex[j]; Index previousStart = m_outerIndex[j];
m_outerIndex[j] = k; m_outerIndex[j] = k;
Index end = m_outerIndex[j+1]; Index end = m_outerIndex[j+1];
for (Index i=previousStart; i<end; ++i) for(Index i=previousStart; i<end; ++i)
{ {
if (!internal::isMuchSmallerThan(m_data.value(i), reference, epsilon)) if(keep(IsRowMajor?j:m_data.index(i), IsRowMajor?m_data.index(i):j, m_data.value(i)))
{ {
m_data.value(k) = m_data.value(i); m_data.value(k) = m_data.value(i);
m_data.index(k) = m_data.index(i); m_data.index(k) = m_data.index(i);