1 // Ceres Solver - A fast non-linear least squares minimizer
2 // Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
3 // http://code.google.com/p/ceres-solver/
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are met:
7 //
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9 // this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above copyright notice,
11 // this list of conditions and the following disclaimer in the documentation
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14 // used to endorse or promote products derived from this software without
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16 //
17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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28 //
29 // Author: sameeragarwal@google.com (Sameer Agarwal)
30
31 #include "ceres/detect_structure.h"
32 #include "ceres/internal/eigen.h"
33 #include "glog/logging.h"
34
35 namespace ceres {
36 namespace internal {
37
DetectStructure(const CompressedRowBlockStructure & bs,const int num_eliminate_blocks,int * row_block_size,int * e_block_size,int * f_block_size)38 void DetectStructure(const CompressedRowBlockStructure& bs,
39 const int num_eliminate_blocks,
40 int* row_block_size,
41 int* e_block_size,
42 int* f_block_size) {
43 const int num_row_blocks = bs.rows.size();
44 *row_block_size = 0;
45 *e_block_size = 0;
46 *f_block_size = 0;
47
48 // Iterate over row blocks of the matrix, checking if row_block,
49 // e_block or f_block sizes remain constant.
50 for (int r = 0; r < num_row_blocks; ++r) {
51 const CompressedRow& row = bs.rows[r];
52 // We do not care about the sizes of the blocks in rows which do
53 // not contain e_blocks.
54 if (row.cells.front().block_id >= num_eliminate_blocks) {
55 break;
56 }
57 const int e_block_id = row.cells.front().block_id;
58
59 if (*row_block_size == 0) {
60 *row_block_size = row.block.size;
61 } else if (*row_block_size != Eigen::Dynamic &&
62 *row_block_size != row.block.size) {
63 VLOG(2) << "Dynamic row block size because the block size changed from "
64 << *row_block_size << " to "
65 << row.block.size;
66 *row_block_size = Eigen::Dynamic;
67 }
68
69
70 if (*e_block_size == 0) {
71 *e_block_size = bs.cols[e_block_id].size;
72 } else if (*e_block_size != Eigen::Dynamic &&
73 *e_block_size != bs.cols[e_block_id].size) {
74 VLOG(2) << "Dynamic e block size because the block size changed from "
75 << *e_block_size << " to "
76 << bs.cols[e_block_id].size;
77 *e_block_size = Eigen::Dynamic;
78 }
79
80 if (*f_block_size == 0) {
81 if (row.cells.size() > 1) {
82 const int f_block_id = row.cells[1].block_id;
83 *f_block_size = bs.cols[f_block_id].size;
84 }
85 } else if (*f_block_size != Eigen::Dynamic) {
86 for (int c = 1; c < row.cells.size(); ++c) {
87 if (*f_block_size != bs.cols[row.cells[c].block_id].size) {
88 VLOG(2) << "Dynamic f block size because the block size "
89 << "changed from " << *f_block_size << " to "
90 << bs.cols[row.cells[c].block_id].size;
91 *f_block_size = Eigen::Dynamic;
92 break;
93 }
94 }
95 }
96
97 const bool is_everything_dynamic = (*row_block_size == Eigen::Dynamic &&
98 *e_block_size == Eigen::Dynamic &&
99 *f_block_size == Eigen::Dynamic);
100 if (is_everything_dynamic) {
101 break;
102 }
103 }
104
105 CHECK_NE(*row_block_size, 0) << "No rows found";
106 CHECK_NE(*e_block_size, 0) << "No e type blocks found";
107 VLOG(1) << "Schur complement static structure <"
108 << *row_block_size << ","
109 << *e_block_size << ","
110 << *f_block_size << ">.";
111 }
112
113 } // namespace internal
114 } // namespace ceres
115