added the SparseView class.

2026-04-10 11:34:33 +08:00 · 2010-06-14 02:16:46 +03:00
parent 9e00697ccc
commit dcd39a96e1
5 changed files with 100 additions and 1 deletions
--- a/Eigen/src/Sparse/SparseView.h
+++ b/Eigen/src/Sparse/SparseView.h
@@ -0,0 +1,95 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2010 Gael Guennebaud <g.gael@free.fr>
+// Copyright (C) 2010 Daniel Lowengrub <lowdanie@gmail.com>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef EIGEN_SPARSEVIEW_H
+#define EIGEN_SPARSEVIEW_H
+
+template<typename MatrixType>
+struct ei_traits<SparseView<MatrixType> > : ei_traits<MatrixType> {};
+
+template<typename MatrixType>
+class SparseView : public SparseMatrixBase<SparseView<MatrixType> >
+{
+public:
+  EIGEN_SPARSE_PUBLIC_INTERFACE(SparseView);
+
+  SparseView(const MatrixType& mat, const Scalar m_reference = Scalar(0),
+             typename NumTraits<Scalar>::Real m_epsilon = NumTraits<Scalar>::dummy_precision()) : 
+    m_matrix(mat), m_reference(m_reference), m_epsilon(m_epsilon) {}
+  class InnerIterator;
+
+  inline Index rows() const { return m_matrix.rows(); }
+  inline Index cols() const { return m_matrix.cols(); }
+
+  inline Index innerSize() const { return m_matrix.innerSize(); }
+  inline Index outerSize() const { return m_matrix.outerSize(); }
+
+protected:
+  const typename MatrixType::Nested m_matrix;
+  Scalar m_reference;
+  typename NumTraits<Scalar>::Real m_epsilon;
+};
+
+template<typename MatrixType>
+class SparseView<MatrixType>::InnerIterator : public MatrixType::InnerIterator
+{
+public:
+  typedef typename MatrixType::InnerIterator IterBase;
+  InnerIterator(const SparseView& view, Index outer) :
+  DenseBase<MatrixType>::InnerIterator(view.m_matrix, outer), m_view(view)
+  {
+    incrementToNonZero();
+  }
+
+  EIGEN_STRONG_INLINE InnerIterator& operator++()
+  {
+    IterBase::operator++();
+    incrementToNonZero();
+    return *this;
+  }
+
+  using IterBase::value;
+
+protected:
+  const SparseView& m_view;
+
+private:
+  void incrementToNonZero()
+  {
+    while(ei_isMuchSmallerThan(value(), m_view.m_reference, m_view.m_epsilon) && (bool(*this)))
+      {
+        IterBase::operator++();
+      }
+  }
+};
+
+template<typename Derived>
+const SparseView<Derived> MatrixBase<Derived>::sparseView(const Scalar m_reference,
+                                                          typename NumTraits<Scalar>::Real m_epsilon) const
+{
+  return SparseView<Derived>(derived(), m_reference, m_epsilon);
+}
+
+#endif