sum_of_matrices.cc
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26
27
28#include "matrices.h"
29#include "double_vector.h"
30#include "sum_of_matrices.h"
31
32
33namespace oomph
34{
35 // =================================================================
36 /// Matrix-vector multiplication for a sumofmatrices class. Just
37 /// delegate each multiplication to the appropriate class then add up the
38 /// results.
39 // =================================================================
41 {
42 // We assume that appropriate checks and initialisation on x and soln are
43 // carried out within the individual matrix multiplys.
44
45 // Multiply for the main matrix
46 Main_matrix_pt->multiply(x, soln);
47
48 // Now add contribution for the added matrices
49 for (unsigned i_matrix = 0; i_matrix < Added_matrix_pt.size(); i_matrix++)
50 {
51 // If possible copy the matrix distribution, otherwise it isn't
52 // distributed so make a serial LinearAlgebraDistribution object.
53 LinearAlgebraDistribution col_dist, row_dist;
54 OomphCommunicator serial_comm; // Serial communcator (does nothing)
55 col_dist.build(&serial_comm, added_matrix_pt(i_matrix)->ncol(), false);
56 row_dist.build(&serial_comm, added_matrix_pt(i_matrix)->nrow(), false);
57
58 // Create temporary output DoubleVector
59 DoubleVector temp_soln(row_dist);
60
61 // Create a const iterator for the map (faster than .find() or []
62 // access, const means can't change the map via the iterator).
63 std::map<unsigned, unsigned>::const_iterator it;
64
65 // Pull out the appropriate values into a temp vector
66 //??ds not parallel
67 DoubleVector temp_x(col_dist);
68 for (it = Col_map_pt[i_matrix]->main_to_added_mapping_pt()->begin();
69 it != Col_map_pt[i_matrix]->main_to_added_mapping_pt()->end();
70 it++)
71 {
72 temp_x[it->second] = x[it->first];
73 }
74
75 // Perform the multiplication
76 Added_matrix_pt[i_matrix]->multiply(temp_x, temp_soln);
77
78 // Add result to solution vector
79 //??ds not parallel
80 for (it = Row_map_pt[i_matrix]->main_to_added_mapping_pt()->begin();
81 it != Row_map_pt[i_matrix]->main_to_added_mapping_pt()->end();
82 it++)
83 {
84 soln[it->first] += temp_soln[it->second];
85 }
86 }
87 }
88
89} // namespace oomph
virtual void multiply(const DoubleVector &x, DoubleVector &soln) const =0
Multiply the matrix by the vector x: soln=Ax.
A vector in the mathematical sense, initially developed for linear algebra type applications....
Definition: double_vector.h:58
Describes the distribution of a distributable linear algebra type object. Typically this is a contain...
void build(const OomphCommunicator *const comm_pt, const unsigned &first_row, const unsigned &nrow_local, const unsigned &nrow=0)
Sets the distribution. Takes first_row, nrow_local and nrow as arguments. If nrow is not provided or ...
An oomph-lib wrapper to the MPI_Comm communicator object. Just contains an MPI_Comm object (which is ...
Definition: communicator.h:54
unsigned long nrow() const
Return the number of rows of the main matrix.
Vector< DoubleMatrixBase * > Added_matrix_pt
List of pointers to the matrices that are added to the main matrix.
Vector< const AddedMainNumberingLookup * > Col_map_pt
List of maps between col numbers of the main matrix and the added matrices.
Vector< const AddedMainNumberingLookup * > Row_map_pt
List of maps between row numbers of the main matrix and the added matrices.
unsigned long ncol() const
Return the number of columns of the main matrix.
void multiply(const DoubleVector &x, DoubleVector &soln) const
Multiply: just call multiply on each of the matrices and add up the results (with appropriate bookeep...
DoubleMatrixBase * added_matrix_pt(const unsigned &i) const
Access function for ith added matrix (main matrix not included in numbering).
DoubleMatrixBase * Main_matrix_pt
Pointer to the matrix which we are adding the others to.
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