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add partial count redux (adapted patch from Ricard Marxer)

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This commit is contained in:
Gael Guennebaud 2009-01-24 15:22:44 +00:00
parent 81b0ab53cf
commit 56c7e164f0
4 changed files with 20 additions and 2 deletions
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13
Eigen/src/Array/PartialRedux.h
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@ -114,6 +114,7 @@ EIGEN_MEMBER_FUNCTOR(minCoeff, (Size-1)*NumTraits<Scalar>::AddCost);
EIGEN_MEMBER_FUNCTOR(maxCoeff, (Size-1)*NumTraits<Scalar>::AddCost);
EIGEN_MEMBER_FUNCTOR(all, (Size-1)*NumTraits<Scalar>::AddCost);
EIGEN_MEMBER_FUNCTOR(any, (Size-1)*NumTraits<Scalar>::AddCost);
EIGEN_MEMBER_FUNCTOR(count, (Size-1)*NumTraits<Scalar>::AddCost);
/** \internal */
template <typename BinaryOp, typename Scalar>
@ -173,7 +174,7 @@ template<typename ExpressionType, int Direction> class PartialRedux
};
typedef typename ExpressionType::PlainMatrixType CrossReturnType;
inline PartialRedux(const ExpressionType& matrix) : m_matrix(matrix) {}
/** \internal */
@ -246,6 +247,16 @@ template<typename ExpressionType, int Direction> class PartialRedux
* \sa MatrixBase::any() */
const typename ReturnType<ei_member_any>::Type any() const
{ return _expression(); }
/** \returns a row (or column) vector expression representing
* the number of \c true coefficients of each respective column (or row).
*
* Example: \include PartialRedux_count.cpp
* Output: \verbinclude PartialRedux_count.out
*
* \sa MatrixBase::count() */
const PartialReduxExpr<ExpressionType, ei_member_count<int>, Direction> count() const
{ return _expression(); }
/** \returns a 3x3 matrix expression of the cross product
* of each column or row of the referenced expression with the \a other vector.

1
doc/TutorialSparse.dox
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@ -21,7 +21,6 @@ namespace Eigen {
In many applications (e.g., finite element methods) it is common to deal with very large matrices where only a few coefficients are different than zero. Both in term of memory consumption and performance, it is fundamental to use an adequate representation storing only nonzero coefficients. Such a matrix is called a sparse matrix.
\b Declaring \b sparse \b matrices \b and \b vectors \n
The SparseMatrix class is the main sparse matrix representation of the Eigen's sparse module which offers high performance, low memory usage, and compatibility with most of sparse linear algebra packages. Because of its limited flexibility, we also provide a DynamicSparseMatrix variante taillored for low-level sparse matrix assembly. Both of them can be either row major or column major:

3
doc/snippets/PartialRedux_count.cpp Normal file
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@ -0,0 +1,3 @@
Matrix3d m = Matrix3d::Random();
cout << "Here is the matrix m:" << endl << m << endl;
cout << "Here is the count of elements larger or equal than 0.5 of each row:" << endl << (m.cwise() >= 0.5).rowwise().count() << endl;

5
test/array.cpp
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@ -111,6 +111,11 @@ template<typename MatrixType> void comparisons(const MatrixType& m)
.select(m1,0), m3);
// even shorter version:
VERIFY_IS_APPROX( (m1.cwise().abs().cwise()<mid).select(0,m1), m3);
// count
VERIFY(((m1.cwise().abs().cwise()+1).cwise()>0.5).count() == rows*cols);
VERIFY_IS_APPROX(((m1.cwise().abs().cwise()+1).cwise()>0.5).colwise().count(), RowVectorXi::Constant(cols,rows));
VERIFY_IS_APPROX(((m1.cwise().abs().cwise()+1).cwise()>0.5).rowwise().count(), VectorXi::Constant(rows, cols));
}
template<typename VectorType> void lpNorm(const VectorType& v)