decompositions: expose PermutationMatrix

include/eigenpy/decompositions/PermutationMatrix.hpp

+/*
+ * Copyright 2024 INRIA
+ */
+
+#ifndef __eigenpy_decomposition_permutation_matrix_hpp__
+#define __eigenpy_decomposition_permutation_matrix_hpp__
+
+#include "eigenpy/eigenpy.hpp"
+#include "eigenpy/eigen/EigenBase.hpp"
+
+namespace eigenpy {
+
+template <int SizeAtCompileTime, int MaxSizeAtCompileTime = SizeAtCompileTime,
+          typename StorageIndex_ = EIGEN_DEFAULT_DENSE_INDEX_TYPE>
+struct PermutationMatrixVisitor
+    : public boost::python::def_visitor<PermutationMatrixVisitor<
+          SizeAtCompileTime, MaxSizeAtCompileTime, StorageIndex_> > {
+  typedef StorageIndex_ StorageIndex;
+  typedef Eigen::PermutationMatrix<SizeAtCompileTime, MaxSizeAtCompileTime,
+                                   StorageIndex>
+      PermutationMatrix;
+  typedef typename PermutationMatrix::DenseMatrixType DenseMatrixType;
+  typedef PermutationMatrix Self;
+  typedef Eigen::Matrix<StorageIndex, SizeAtCompileTime, 1, 0,
+                        MaxSizeAtCompileTime, 1>
+      VectorIndex;
+
+  template <class PyClass>
+  void visit(PyClass &cl) const {
+    cl.def(bp::init<const Eigen::DenseIndex>(bp::args("self", "size"),
+                                             "Default constructor"))
+        .def(bp::init<VectorIndex>(
+            bp::args("self", "indices"),
+            "The indices array has the meaning that the permutations sends "
+            "each integer i to indices[i].\n"
+            "It is your responsibility to check that the indices array that "
+            "you passes actually describes a permutation, i.e., each value "
+            "between 0 and n-1 occurs exactly once, where n is the array's "
+            "size."))
+
+        .def(
+            "indices",
+            +[](const PermutationMatrix &self) {
+              return VectorIndex(self.indices());
+            },
+            bp::arg("self"), "The stored array representing the permutation.")
+
+        .def("applyTranspositionOnTheLeft",
+             &PermutationMatrix::applyTranspositionOnTheLeft,
+             bp::args("self", "i", "j"),
+             "Multiplies self by the transposition (ij) on the left.",
+             bp::return_self<>())
+        .def("applyTranspositionOnTheRight",
+             &PermutationMatrix::applyTranspositionOnTheRight,
+             bp::args("self", "i", "j"),
+             "Multiplies self by the transposition (ij) on the right.",
+             bp::return_self<>())
+
+        .def("setIdentity",
+             (void(PermutationMatrix::*)()) & PermutationMatrix::setIdentity,
+             bp::arg("self"),
+             "Sets self to be the identity permutation matrix.")
+        .def("setIdentity",
+             (void(PermutationMatrix::*)(Eigen::DenseIndex)) &
+                 PermutationMatrix::setIdentity,
+             bp::args("self", "size"),
+             "Sets self to be the identity permutation matrix of given size.")
+
+        .def("toDenseMatrix", &PermutationMatrix::toDenseMatrix,
+             bp::arg("self"),
+             "Returns a numpy array object initialized from this permutation "
+             "matrix.")
+
+        .def(
+            "transpose",
+            +[](const PermutationMatrix &self) -> PermutationMatrix {
+              return self.transpose();
+            },
+            bp::arg("self"), "Returns the tranpose permutation matrix.")
+        .def(
+            "inverse",
+            +[](const PermutationMatrix &self) -> PermutationMatrix {
+              return self.inverse();
+            },
+            bp::arg("self"), "Returns the inverse permutation matrix.")
+
+        .def("resize", &PermutationMatrix::resize, bp::args("self", "size"),
+             "Resizes to given size.")
+
+        .def(bp::self * bp::self)
+        .def(EigenBaseVisitor<Self>());
+  }
+
+  static void expose(const std::string &name) {
+    bp::class_<PermutationMatrix>(name.c_str(),
+                                  "Permutation matrix.\n"
+                                  "This class represents a permutation matrix, "
+                                  "internally stored as a vector of integers.",
+                                  bp::no_init)
+        .def(PermutationMatrixVisitor());
+  }
+};
+
+}  // namespace eigenpy
+
+#endif  // ifndef __eigenpy_decomposition_permutation_matrix_hpp__

src/decompositions/decompositions.cpp

@@ -7,6 +7,7 @@
 #include "eigenpy/decompositions/EigenSolver.hpp"
 #include "eigenpy/decompositions/LDLT.hpp"
 #include "eigenpy/decompositions/LLT.hpp"
+#include "eigenpy/decompositions/PermutationMatrix.hpp"
 #include "eigenpy/decompositions/sparse/LLT.hpp"
 #include "eigenpy/decompositions/sparse/LDLT.hpp"
 #include "eigenpy/decompositions/SelfAdjointEigenSolver.hpp"
@@ -45,5 +46,7 @@ void exposeDecompositions() {
     SimplicialLLTVisitor<ColMajorSparseMatrix>::expose("SimplicialLLT");
     SimplicialLDLTVisitor<ColMajorSparseMatrix>::expose("SimplicialLDLT");
   }
+
+  PermutationMatrixVisitor<Eigen::Dynamic>::expose("PermutationMatrix");
 }
 }  // namespace eigenpy