1// Ceres Solver - A fast non-linear least squares minimizer
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29// Author: sameeragarwal@google.com (Sameer Agarwal)
30
31#include "ceres/incomplete_lq_factorization.h"
32
33#include "Eigen/Dense"
34#include "ceres/compressed_row_sparse_matrix.h"
35#include "ceres/internal/scoped_ptr.h"
36#include "glog/logging.h"
37#include "gtest/gtest.h"
38
39namespace ceres {
40namespace internal {
41
42void ExpectMatricesAreEqual(const CompressedRowSparseMatrix& expected,
43                            const CompressedRowSparseMatrix& actual,
44                            const double tolerance) {
45  EXPECT_EQ(expected.num_rows(), actual.num_rows());
46  EXPECT_EQ(expected.num_cols(), actual.num_cols());
47  for (int i = 0; i < expected.num_rows(); ++i) {
48    EXPECT_EQ(expected.rows()[i], actual.rows()[i]);
49  }
50
51  for (int i = 0; i < actual.num_nonzeros(); ++i) {
52    EXPECT_EQ(expected.cols()[i], actual.cols()[i]);
53    EXPECT_NEAR(expected.values()[i], actual.values()[i], tolerance);
54  }
55}
56
57TEST(IncompleteQRFactorization, OneByOneMatrix) {
58  CompressedRowSparseMatrix matrix(1, 1, 1);
59  matrix.mutable_rows()[0] = 0;
60  matrix.mutable_rows()[1] = 1;
61  matrix.mutable_cols()[0] = 0;
62  matrix.mutable_values()[0] = 2;
63
64  scoped_ptr<CompressedRowSparseMatrix> l(
65      IncompleteLQFactorization(matrix, 1, 0.0, 1, 0.0));
66  ExpectMatricesAreEqual(matrix, *l, 1e-16);
67}
68
69TEST(IncompleteLQFactorization, CompleteFactorization) {
70  double dense_matrix[] = {
71    0.00000,  0.00000,  0.20522,  0.00000,  0.49077,  0.92835,  0.00000,  0.83825,  0.00000,  0.00000,  // NOLINT
72    0.00000,  0.00000,  0.00000,  0.62491,  0.38144,  0.00000,  0.79394,  0.79178,  0.00000,  0.44382,  // NOLINT
73    0.00000,  0.00000,  0.00000,  0.61517,  0.55941,  0.00000,  0.00000,  0.00000,  0.00000,  0.60664,  // NOLINT
74    0.00000,  0.00000,  0.00000,  0.00000,  0.45031,  0.00000,  0.64132,  0.00000,  0.38832,  0.00000,  // NOLINT
75    0.00000,  0.00000,  0.00000,  0.00000,  0.00000,  0.57121,  0.00000,  0.01375,  0.70640,  0.00000,  // NOLINT
76    0.00000,  0.00000,  0.07451,  0.00000,  0.00000,  0.00000,  0.00000,  0.00000,  0.00000,  0.00000,  // NOLINT
77    0.68095,  0.00000,  0.00000,  0.95473,  0.00000,  0.00000,  0.00000,  0.00000,  0.00000,  0.00000,  // NOLINT
78    0.00000,  0.00000,  0.00000,  0.00000,  0.59374,  0.00000,  0.00000,  0.00000,  0.49139,  0.00000,  // NOLINT
79    0.91276,  0.96641,  0.00000,  0.00000,  0.00000,  0.00000,  0.00000,  0.00000,  0.00000,  0.91797,  // NOLINT
80    0.96828,  0.00000,  0.00000,  0.72583,  0.00000,  0.00000,  0.81459,  0.00000,  0.04560,  0.00000   // NOLINT
81  };
82
83  CompressedRowSparseMatrix matrix(10, 10, 100);
84  int* rows = matrix.mutable_rows();
85  int* cols = matrix.mutable_cols();
86  double* values = matrix.mutable_values();
87
88  int idx = 0;
89  for (int i = 0; i < 10; ++i) {
90    rows[i] = idx;
91    for (int j = 0; j < 10; ++j) {
92      const double v = dense_matrix[i * 10 + j];
93      if (fabs(v) > 1e-6) {
94        cols[idx] = j;
95        values[idx] = v;
96        ++idx;
97      }
98    }
99  }
100  rows[10] = idx;
101
102  scoped_ptr<CompressedRowSparseMatrix> lmatrix(
103      IncompleteLQFactorization(matrix, 10, 0.0, 10, 0.0));
104
105  ConstMatrixRef mref(dense_matrix, 10, 10);
106
107  // Use Cholesky factorization to compute the L matrix.
108  Matrix expected_l_matrix  = (mref * mref.transpose()).llt().matrixL();
109  Matrix actual_l_matrix;
110  lmatrix->ToDenseMatrix(&actual_l_matrix);
111
112  EXPECT_NEAR((expected_l_matrix * expected_l_matrix.transpose() -
113               actual_l_matrix * actual_l_matrix.transpose()).norm(),
114              0.0,
115              1e-10)
116      << "expected: \n" << expected_l_matrix
117      << "\actual: \n" << actual_l_matrix;
118}
119
120TEST(IncompleteLQFactorization, DropEntriesAndAddRow) {
121  // Allocate space and then make it a zero sized matrix.
122  CompressedRowSparseMatrix matrix(10, 10, 100);
123  matrix.set_num_rows(0);
124
125  vector<pair<int, double> > scratch(10);
126
127  Vector dense_vector(10);
128  dense_vector(0) = 5;
129  dense_vector(1) = 1;
130  dense_vector(2) = 2;
131  dense_vector(3) = 3;
132  dense_vector(4) = 1;
133  dense_vector(5) = 4;
134
135  // Add a row with just one entry.
136  DropEntriesAndAddRow(dense_vector, 1, 1, 0, &scratch, &matrix);
137  EXPECT_EQ(matrix.num_rows(), 1);
138  EXPECT_EQ(matrix.num_cols(), 10);
139  EXPECT_EQ(matrix.num_nonzeros(), 1);
140  EXPECT_EQ(matrix.values()[0], 5.0);
141  EXPECT_EQ(matrix.cols()[0], 0);
142
143  // Add a row with six entries
144  DropEntriesAndAddRow(dense_vector, 6, 10, 0, &scratch, &matrix);
145  EXPECT_EQ(matrix.num_rows(), 2);
146  EXPECT_EQ(matrix.num_cols(), 10);
147  EXPECT_EQ(matrix.num_nonzeros(), 7);
148  for (int idx = matrix.rows()[1]; idx < matrix.rows()[2]; ++idx) {
149    EXPECT_EQ(matrix.cols()[idx], idx - matrix.rows()[1]);
150    EXPECT_EQ(matrix.values()[idx], dense_vector(idx - matrix.rows()[1]));
151  }
152
153  // Add the top 3 entries.
154  DropEntriesAndAddRow(dense_vector, 6, 3, 0, &scratch, &matrix);
155  EXPECT_EQ(matrix.num_rows(), 3);
156  EXPECT_EQ(matrix.num_cols(), 10);
157  EXPECT_EQ(matrix.num_nonzeros(), 10);
158
159  EXPECT_EQ(matrix.cols()[matrix.rows()[2]], 0);
160  EXPECT_EQ(matrix.cols()[matrix.rows()[2] + 1], 3);
161  EXPECT_EQ(matrix.cols()[matrix.rows()[2] + 2], 5);
162
163  EXPECT_EQ(matrix.values()[matrix.rows()[2]], 5);
164  EXPECT_EQ(matrix.values()[matrix.rows()[2] + 1], 3);
165  EXPECT_EQ(matrix.values()[matrix.rows()[2] + 2], 4);
166
167  // Only keep entries greater than 1.0;
168  DropEntriesAndAddRow(dense_vector, 6, 6, 0.2, &scratch, &matrix);
169  EXPECT_EQ(matrix.num_rows(), 4);
170  EXPECT_EQ(matrix.num_cols(), 10);
171  EXPECT_EQ(matrix.num_nonzeros(), 14);
172
173  EXPECT_EQ(matrix.cols()[matrix.rows()[3]], 0);
174  EXPECT_EQ(matrix.cols()[matrix.rows()[3] + 1], 2);
175  EXPECT_EQ(matrix.cols()[matrix.rows()[3] + 2], 3);
176  EXPECT_EQ(matrix.cols()[matrix.rows()[3] + 3], 5);
177
178  EXPECT_EQ(matrix.values()[matrix.rows()[3]], 5);
179  EXPECT_EQ(matrix.values()[matrix.rows()[3] + 1], 2);
180  EXPECT_EQ(matrix.values()[matrix.rows()[3] + 2], 3);
181  EXPECT_EQ(matrix.values()[matrix.rows()[3] + 3], 4);
182
183  // Only keep the top 2 entries greater than 1.0
184  DropEntriesAndAddRow(dense_vector, 6, 2, 0.2, &scratch, &matrix);
185  EXPECT_EQ(matrix.num_rows(), 5);
186  EXPECT_EQ(matrix.num_cols(), 10);
187  EXPECT_EQ(matrix.num_nonzeros(), 16);
188
189  EXPECT_EQ(matrix.cols()[matrix.rows()[4]], 0);
190  EXPECT_EQ(matrix.cols()[matrix.rows()[4] + 1], 5);
191
192  EXPECT_EQ(matrix.values()[matrix.rows()[4]], 5);
193  EXPECT_EQ(matrix.values()[matrix.rows()[4] + 1], 4);
194}
195
196
197}  // namespace internal
198}  // namespace ceres
199