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Add doc for IndexedView

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Gael Guennebaud 2017-01-10 16:28:57 +01:00
parent 87963f441c
commit b47a7e5c3a
1 changed files with 45 additions and 2 deletions
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47
Eigen/src/Core/IndexedView.h
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@ -55,13 +55,49 @@ struct traits<IndexedView<XprType, RowIndices, ColIndices> >
typedef Block<XprType,RowsAtCompileTime,ColsAtCompileTime,IsInnerPannel> BlockType;
};
}
template<typename XprType, typename RowIndices, typename ColIndices, typename StorageKind>
class IndexedViewImpl;
// Expression of a generic slice
/** \class IndexedView
* \ingroup Core_Module
*
* \brief Expression of a non-sequential sub-matrix defined by arbitrary sequences of row and column indices
*
* \tparam XprType the type of the expression in which we are taking the intersections of sub-rows and sub-columns
* \tparam RowIndices the type of the object defining the sequence of row indices
* \tparam ColIndices the type of the object defining the sequence of column indices
*
* This class represents an expression of a sub-matrix (or sub-vector) defined as the intersection
* of sub-sets of rows and columns, that are themself defined by generic sequences of row indices \f${r_0,r_1,..r_{m-1}\f$
* and column indices \f${c_0,c_1,..c_{n-1}\f$. Let \f$ A \f$ be the nested matrix, then the resulting matrix \f$ B \f$ has \c m
* rows and \c n columns, and its entries are given by: \f$ B(i,j) = A(r_i,c_j) \f$.
*
* The \c RowIndices and \c ColIndices types must be compatible with the following API:
* \code
* <integral type> operator[](Index) const;
* Index size() const;
* \endcode
*
* Typical supported types thus include:
* - std::vector<int>
* - std::valarray<int>
* - std::array<int>
* - c++ arrays: int[N]
* - Eigen::ArrayXi
* - decltype(ArrayXi::LinSpaced(...))
* - Any view/expressions of the previous types
* - Eigen::ArithmeticSequence
* - Eigen::AllRange (helper for Eigen::all)
* - Eigen::IntAsArray (helper for single index)
* - etc.
*
* In typical usages of %Eigen, this class should never be used directly. It is the return type of DenseBase::operator().
*
* \sa class Block
*/
template<typename XprType, typename RowIndices, typename ColIndices>
class IndexedView : public IndexedViewImpl<XprType, RowIndices, ColIndices, typename internal::traits<XprType>::StorageKind>
{
@ -76,7 +112,11 @@ public:
IndexedView(XprType& xpr, const T0& rowIndices, const T1& colIndices)
: m_xpr(xpr), m_rowIndices(rowIndices), m_colIndices(colIndices)
{}
/** \returns number of rows */
Index rows() const { return internal::size(m_rowIndices); }
/** \returns number of columns */
Index cols() const { return internal::size(m_colIndices); }
/** \returns the nested expression */
@ -87,7 +127,10 @@ public:
typename internal::remove_reference<XprType>::type&
nestedExpression() { return m_xpr.const_cast_derived(); }
/** \returns a const reference to the object storing/generating the row indices */
const RowIndices& rowIndices() const { return m_rowIndices; }
/** \returns a const reference to the object storing/generating the column indices */
const ColIndices& colIndices() const { return m_colIndices; }
protected: