Diff: src/Core/Visitor.h
- Revision:
- 0:13a5d365ba16
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Core/Visitor.h Thu Oct 13 04:07:23 2016 +0000
@@ -0,0 +1,240 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef EIGEN_VISITOR_H
+#define EIGEN_VISITOR_H
+
+namespace Eigen {
+
+namespace internal {
+
+template<typename Visitor, typename Derived, int UnrollCount>
+struct visitor_impl
+{
+ enum {
+ col = (UnrollCount-1) / Derived::RowsAtCompileTime,
+ row = (UnrollCount-1) % Derived::RowsAtCompileTime
+ };
+
+ static inline void run(const Derived &mat, Visitor& visitor)
+ {
+ visitor_impl<Visitor, Derived, UnrollCount-1>::run(mat, visitor);
+ visitor(mat.coeff(row, col), row, col);
+ }
+};
+
+template<typename Visitor, typename Derived>
+struct visitor_impl<Visitor, Derived, 1>
+{
+ static inline void run(const Derived &mat, Visitor& visitor)
+ {
+ return visitor.init(mat.coeff(0, 0), 0, 0);
+ }
+};
+
+template<typename Visitor, typename Derived>
+struct visitor_impl<Visitor, Derived, Dynamic>
+{
+ typedef typename Derived::Index Index;
+ static inline void run(const Derived& mat, Visitor& visitor)
+ {
+ visitor.init(mat.coeff(0,0), 0, 0);
+ for(Index i = 1; i < mat.rows(); ++i)
+ visitor(mat.coeff(i, 0), i, 0);
+ for(Index j = 1; j < mat.cols(); ++j)
+ for(Index i = 0; i < mat.rows(); ++i)
+ visitor(mat.coeff(i, j), i, j);
+ }
+};
+
+} // end namespace internal
+
+/** Applies the visitor \a visitor to the whole coefficients of the matrix or vector.
+ *
+ * The template parameter \a Visitor is the type of the visitor and provides the following interface:
+ * \code
+ * struct MyVisitor {
+ * // called for the first coefficient
+ * void init(const Scalar& value, Index i, Index j);
+ * // called for all other coefficients
+ * void operator() (const Scalar& value, Index i, Index j);
+ * };
+ * \endcode
+ *
+ * \note compared to one or two \em for \em loops, visitors offer automatic
+ * unrolling for small fixed size matrix.
+ *
+ * \sa minCoeff(Index*,Index*), maxCoeff(Index*,Index*), DenseBase::redux()
+ */
+template<typename Derived>
+template<typename Visitor>
+void DenseBase<Derived>::visit(Visitor& visitor) const
+{
+ typedef typename internal::remove_all<typename Derived::Nested>::type ThisNested;
+ typename Derived::Nested thisNested(derived());
+
+ enum { unroll = SizeAtCompileTime != Dynamic
+ && CoeffReadCost != Dynamic
+ && (SizeAtCompileTime == 1 || internal::functor_traits<Visitor>::Cost != Dynamic)
+ && SizeAtCompileTime * CoeffReadCost + (SizeAtCompileTime-1) * internal::functor_traits<Visitor>::Cost
+ <= EIGEN_UNROLLING_LIMIT };
+ return internal::visitor_impl<Visitor, ThisNested,
+ unroll ? int(SizeAtCompileTime) : Dynamic
+ >::run(thisNested, visitor);
+}
+
+namespace internal {
+
+/** \internal
+ * \brief Base class to implement min and max visitors
+ */
+template <typename Derived>
+struct coeff_visitor
+{
+ typedef typename Derived::Index Index;
+ typedef typename Derived::Scalar Scalar;
+ Index row, col;
+ Scalar res;
+ inline void init(const Scalar& value, Index i, Index j)
+ {
+ res = value;
+ row = i;
+ col = j;
+ }
+};
+
+/** \internal
+ * \brief Visitor computing the min coefficient with its value and coordinates
+ *
+ * \sa DenseBase::minCoeff(Index*, Index*)
+ */
+template <typename Derived>
+struct min_coeff_visitor : coeff_visitor<Derived>
+{
+ typedef typename Derived::Index Index;
+ typedef typename Derived::Scalar Scalar;
+ void operator() (const Scalar& value, Index i, Index j)
+ {
+ if(value < this->res)
+ {
+ this->res = value;
+ this->row = i;
+ this->col = j;
+ }
+ }
+};
+
+template<typename Scalar>
+struct functor_traits<min_coeff_visitor<Scalar> > {
+ enum {
+ Cost = NumTraits<Scalar>::AddCost
+ };
+};
+
+/** \internal
+ * \brief Visitor computing the max coefficient with its value and coordinates
+ *
+ * \sa DenseBase::maxCoeff(Index*, Index*)
+ */
+template <typename Derived>
+struct max_coeff_visitor : coeff_visitor<Derived>
+{
+ typedef typename Derived::Index Index;
+ typedef typename Derived::Scalar Scalar;
+ void operator() (const Scalar& value, Index i, Index j)
+ {
+ if(value > this->res)
+ {
+ this->res = value;
+ this->row = i;
+ this->col = j;
+ }
+ }
+};
+
+template<typename Scalar>
+struct functor_traits<max_coeff_visitor<Scalar> > {
+ enum {
+ Cost = NumTraits<Scalar>::AddCost
+ };
+};
+
+} // end namespace internal
+
+/** \returns the minimum of all coefficients of *this and puts in *row and *col its location.
+ * \warning the result is undefined if \c *this contains NaN.
+ *
+ * \sa DenseBase::minCoeff(Index*), DenseBase::maxCoeff(Index*,Index*), DenseBase::visitor(), DenseBase::minCoeff()
+ */
+template<typename Derived>
+template<typename IndexType>
+typename internal::traits<Derived>::Scalar
+DenseBase<Derived>::minCoeff(IndexType* rowId, IndexType* colId) const
+{
+ internal::min_coeff_visitor<Derived> minVisitor;
+ this->visit(minVisitor);
+ *rowId = minVisitor.row;
+ if (colId) *colId = minVisitor.col;
+ return minVisitor.res;
+}
+
+/** \returns the minimum of all coefficients of *this and puts in *index its location.
+ * \warning the result is undefined if \c *this contains NaN.
+ *
+ * \sa DenseBase::minCoeff(IndexType*,IndexType*), DenseBase::maxCoeff(IndexType*,IndexType*), DenseBase::visitor(), DenseBase::minCoeff()
+ */
+template<typename Derived>
+template<typename IndexType>
+typename internal::traits<Derived>::Scalar
+DenseBase<Derived>::minCoeff(IndexType* index) const
+{
+ EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
+ internal::min_coeff_visitor<Derived> minVisitor;
+ this->visit(minVisitor);
+ *index = (RowsAtCompileTime==1) ? minVisitor.col : minVisitor.row;
+ return minVisitor.res;
+}
+
+/** \returns the maximum of all coefficients of *this and puts in *row and *col its location.
+ * \warning the result is undefined if \c *this contains NaN.
+ *
+ * \sa DenseBase::minCoeff(IndexType*,IndexType*), DenseBase::visitor(), DenseBase::maxCoeff()
+ */
+template<typename Derived>
+template<typename IndexType>
+typename internal::traits<Derived>::Scalar
+DenseBase<Derived>::maxCoeff(IndexType* rowPtr, IndexType* colPtr) const
+{
+ internal::max_coeff_visitor<Derived> maxVisitor;
+ this->visit(maxVisitor);
+ *rowPtr = maxVisitor.row;
+ if (colPtr) *colPtr = maxVisitor.col;
+ return maxVisitor.res;
+}
+
+/** \returns the maximum of all coefficients of *this and puts in *index its location.
+ * \warning the result is undefined if \c *this contains NaN.
+ *
+ * \sa DenseBase::maxCoeff(IndexType*,IndexType*), DenseBase::minCoeff(IndexType*,IndexType*), DenseBase::visitor(), DenseBase::maxCoeff()
+ */
+template<typename Derived>
+template<typename IndexType>
+typename internal::traits<Derived>::Scalar
+DenseBase<Derived>::maxCoeff(IndexType* index) const
+{
+ EIGEN_STATIC_ASSERT_VECTOR_ONLY(Derived)
+ internal::max_coeff_visitor<Derived> maxVisitor;
+ this->visit(maxVisitor);
+ *index = (RowsAtCompileTime==1) ? maxVisitor.col : maxVisitor.row;
+ return maxVisitor.res;
+}
+
+} // end namespace Eigen
+
+#endif // EIGEN_VISITOR_H
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