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doc: Explain type of result for VectorwiseOp member functions.

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Prompted by a question on the forum.
This commit is contained in:
Jitse Niesen 2013-08-06 09:49:44 +01:00
parent 2f0faf117e
commit 616f9cc593
2 changed files with 13 additions and 2 deletions
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11
Eigen/src/Core/VectorwiseOp.h
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@ -301,6 +301,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
/** \returns a row (or column) vector expression of the squared norm
* of each column (or row) of the referenced expression.
* This is a vector with real entries, even if the original matrix has complex entries.
*
* Example: \include PartialRedux_squaredNorm.cpp
* Output: \verbinclude PartialRedux_squaredNorm.out
@ -311,6 +312,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
/** \returns a row (or column) vector expression of the norm
* of each column (or row) of the referenced expression.
* This is a vector with real entries, even if the original matrix has complex entries.
*
* Example: \include PartialRedux_norm.cpp
* Output: \verbinclude PartialRedux_norm.out
@ -322,7 +324,8 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
/** \returns a row (or column) vector expression of the norm
* of each column (or row) of the referenced expression, using
* blue's algorithm.
* Blue's algorithm.
* This is a vector with real entries, even if the original matrix has complex entries.
*
* \sa DenseBase::blueNorm() */
const typename ReturnType<internal::member_blueNorm,RealScalar>::Type blueNorm() const
@ -332,6 +335,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
/** \returns a row (or column) vector expression of the norm
* of each column (or row) of the referenced expression, avoiding
* underflow and overflow.
* This is a vector with real entries, even if the original matrix has complex entries.
*
* \sa DenseBase::stableNorm() */
const typename ReturnType<internal::member_stableNorm,RealScalar>::Type stableNorm() const
@ -341,6 +345,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
/** \returns a row (or column) vector expression of the norm
* of each column (or row) of the referenced expression, avoiding
* underflow and overflow using a concatenation of hypot() calls.
* This is a vector with real entries, even if the original matrix has complex entries.
*
* \sa DenseBase::hypotNorm() */
const typename ReturnType<internal::member_hypotNorm,RealScalar>::Type hypotNorm() const
@ -365,6 +370,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
/** \returns a row (or column) vector expression representing
* whether \b all coefficients of each respective column (or row) are \c true.
* This expression can be assigned to a vector with entries of type \c bool.
*
* \sa DenseBase::all() */
const typename ReturnType<internal::member_all>::Type all() const
@ -372,6 +378,7 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
/** \returns a row (or column) vector expression representing
* whether \b at \b least one coefficient of each respective column (or row) is \c true.
* This expression can be assigned to a vector with entries of type \c bool.
*
* \sa DenseBase::any() */
const typename ReturnType<internal::member_any>::Type any() const
@ -379,6 +386,8 @@ template<typename ExpressionType, int Direction> class VectorwiseOp
/** \returns a row (or column) vector expression representing
* the number of \c true coefficients of each respective column (or row).
* This expression can be assigned to a vector whose entries have the same type as is used to
* index entries of the original matrix; for dense matrices, this is \c std::ptrdiff_t .
*
* Example: \include PartialRedux_count.cpp
* Output: \verbinclude PartialRedux_count.out

4
doc/snippets/PartialRedux_count.cpp
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@ -1,3 +1,5 @@
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.array() >= 0.5).rowwise().count() << endl;
Matrix<ptrdiff_t, 3, 1> res = (m.array() >= 0.5).rowwise().count();
cout << "Here is the count of elements larger or equal than 0.5 of each row:" << endl;
cout << res << endl;