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Ifpack_UserPartitioner.cpp
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42 
43 #include "Ifpack_ConfigDefs.h"
44 #include "Ifpack_Partitioner.h"
46 #include "Ifpack_UserPartitioner.h"
47 #include "Epetra_CrsGraph.h"
48 
49 //==============================================================================
51 {
52 
53  if (Map_ == 0)
54  IFPACK_CHK_ERR(-1);
55 
56  if(keepSingletons_) {
57  // If we're keeping singletons, we need to count them and add a new part
58  // per singleton
59  int base_num_parts = NumLocalParts();
60  int curr_num_parts = base_num_parts;
61 
62  for (int i = 0 ; i < NumMyRows() ; ++i) {
63  if(Map_[i] != -1)
64  Partition_[i] = Map_[i];
65  else {
66  Partition_[i] = curr_num_parts;
67  curr_num_parts++;
68  }
69  }
70 
71  if(curr_num_parts != base_num_parts) {
72  NumLocalParts_ = curr_num_parts;
73  Parts_.resize(NumLocalParts());
74  }
75  }
76  else {
77  // copy the user's vector
78  for (int i = 0 ; i < NumMyRows() ; ++i) {
79  Partition_[i] = Map_[i];
80  }
81  }
82 
83 
84 #if 0
85  // put together all partitions composed by 1 one vertex
86  // (if any)
87  std::vector<int> singletons(NumLocalParts());
88  for (unsigned int i = 0 ; i < singletons.size() ; ++i) {
89  singletons[i] = 0;
90  }
91 
92 
93  // may want to uncomment the following to ensure that no
94  // partitions are in fact singletons
95  for (int i = 0 ; i < NumMyRows() ; ++i) {
96  ++singletons[Partition_[i]];
97  }
98 
99  int count = 0;
100  for (unsigned int i = 0 ; i < singletons.size() ; ++i) {
101  if (singletons[i] == 1)
102  ++count;
103  }
104 
105  int index = -1;
106  for (int i = 0 ; i < NumMyRows() ; ++i) {
107  int j = Partition_[i];
108  if (singletons[j] == 1) {
109  if (index == -1)
110  index = j;
111  else
112  Partition_[i] = index;
113  }
114  }
115 #endif
116 
117  return(0);
118 }
int NumMyRows() const
Returns the number of local rows.
std::vector< int > Partition_
Partition_[i] contains the ID of non-overlapping part it belongs to.
int ComputePartitions()
Computes the partitions. Returns 0 if successful.
int NumLocalParts_
Number of local subgraphs.
int NumLocalParts() const
Returns the number of computed local partitions.
std::vector< std::vector< int > > Parts_
Parts_[i][j] is the ID of the j-th row contained in the (overlapping)
#define IFPACK_CHK_ERR(ifpack_err)