Ifpack2 Templated Preconditioning Package  Version 1.0
Ifpack2_Details_MultiVectorLocalGatherScatter.hpp
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42 
43 #ifndef IFPACK2_DETAILS_MULTIVECTORLOCALGATHERSCATTER_HPP
44 #define IFPACK2_DETAILS_MULTIVECTORLOCALGATHERSCATTER_HPP
45 
49 
50 #include "Tpetra_MultiVector.hpp"
51 #include "Tpetra_Map.hpp"
52 
53 namespace Ifpack2 {
54 namespace Details {
55 
84 template<class MV_in, class MV_out>
86 public:
87  void
88  gather (MV_out& X_out,
89  const MV_in& X_in,
90  const Teuchos::ArrayView<const typename MV_in::local_ordinal_type>& perm) const
91  {
92  using Teuchos::ArrayRCP;
93  const size_t numRows = X_out.getLocalLength ();
94  const size_t numVecs = X_in.getNumVectors ();
95 
96  for (size_t j = 0; j < numVecs; ++j) {
97  ArrayRCP<const typename MV_in::scalar_type> X_in_j = X_in.getData (j);
98  ArrayRCP<typename MV_out::scalar_type> X_out_j = X_out.getDataNonConst (j);
99 
100  for (size_t i = 0; i < numRows; ++i) {
101  const size_t i_perm = perm[i];
102  X_out_j[i] = X_in_j[i_perm];
103  }
104  }
105  }
106 
107  void
108  scatter (MV_in& X_in,
109  const MV_out& X_out,
110  const Teuchos::ArrayView<const typename MV_in::local_ordinal_type>& perm) const
111  {
112  using Teuchos::ArrayRCP;
113  const size_t numRows = X_out.getLocalLength ();
114  const size_t numVecs = X_in.getNumVectors ();
115 
116  for (size_t j = 0; j < numVecs; ++j) {
117  ArrayRCP<typename MV_in::scalar_type> X_in_j = X_in.getDataNonConst (j);
118  ArrayRCP<const typename MV_out::scalar_type> X_out_j = X_out.getData (j);
119 
120  for (size_t i = 0; i < numRows; ++i) {
121  const size_t i_perm = perm[i];
122  X_in_j[i_perm] = X_out_j[i];
123  }
124  }
125  }
126 };
127 
128 } // namespace Details
129 } // namespace Ifpack2
130 
131 #endif // IFPACK2_DETAILS_MULTIVECTORLOCALGATHERSCATTER_HPP
Ifpack2 implementation details.
Preconditioners and smoothers for Tpetra sparse matrices.
Definition: Ifpack2_AdditiveSchwarz_decl.hpp:72
Implementation detail of Ifpack2::Container subclasses.
Definition: Ifpack2_Details_MultiVectorLocalGatherScatter.hpp:85