internal/ceres/compressed_row_sparse_matrix_test.cc - ceres-solver - Git at Google

 // Ceres Solver - A fast non-linear least squares minimizer
 // Copyright 2022 Google Inc. All rights reserved.
 // http://ceres-solver.org/
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are met:
 //
 // * Redistributions of source code must retain the above copyright notice,
 //   this list of conditions and the following disclaimer.
 // * Redistributions in binary form must reproduce the above copyright notice,
 //   this list of conditions and the following disclaimer in the documentation
 //   and/or other materials provided with the distribution.
 // * Neither the name of Google Inc. nor the names of its contributors may be
 //   used to endorse or promote products derived from this software without
 //   specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 // POSSIBILITY OF SUCH DAMAGE.
 //
 // Author: sameeragarwal@google.com (Sameer Agarwal)

 #include "ceres/compressed_row_sparse_matrix.h"

 #include <algorithm>
 #include <memory>
 #include <numeric>
 #include <random>
 #include <string>
 #include <vector>

 #include "Eigen/SparseCore"
 #include "ceres/casts.h"
 #include "ceres/crs_matrix.h"
 #include "ceres/internal/eigen.h"
 #include "ceres/linear_least_squares_problems.h"
 #include "ceres/triplet_sparse_matrix.h"
 #include "glog/logging.h"
 #include "gtest/gtest.h"

 namespace ceres::internal {

 static void CompareMatrices(const SparseMatrix* a, const SparseMatrix* b) {
   EXPECT_EQ(a->num_rows(), b->num_rows());
   EXPECT_EQ(a->num_cols(), b->num_cols());

   int num_rows = a->num_rows();
   int num_cols = a->num_cols();

   for (int i = 0; i < num_cols; ++i) {
     Vector x = Vector::Zero(num_cols);
     x(i) = 1.0;

     Vector y_a = Vector::Zero(num_rows);
     Vector y_b = Vector::Zero(num_rows);

     a->RightMultiplyAndAccumulate(x.data(), y_a.data());
     b->RightMultiplyAndAccumulate(x.data(), y_b.data());
     EXPECT_EQ((y_a - y_b).norm(), 0);
   }
 }

 class CompressedRowSparseMatrixTest : public ::testing::Test {
  protected:
   void SetUp() final {
     auto problem = CreateLinearLeastSquaresProblemFromId(1);

     CHECK(problem != nullptr);

     tsm.reset(down_cast<TripletSparseMatrix*>(problem->A.release()));
     crsm = CompressedRowSparseMatrix::FromTripletSparseMatrix(*tsm);

     num_rows = tsm->num_rows();
     num_cols = tsm->num_cols();

     std::vector<Block>* row_blocks = crsm->mutable_row_blocks();
     row_blocks->resize(num_rows);
     for (int i = 0; i < row_blocks->size(); ++i) {
       (*row_blocks)[i] = Block(1, i);
     }
     std::vector<Block>* col_blocks = crsm->mutable_col_blocks();
     col_blocks->resize(num_cols);
     for (int i = 0; i < col_blocks->size(); ++i) {
       (*col_blocks)[i] = Block(1, i);
     }
   }

   int num_rows;
   int num_cols;

   std::unique_ptr<TripletSparseMatrix> tsm;
   std::unique_ptr<CompressedRowSparseMatrix> crsm;
 };

 TEST_F(CompressedRowSparseMatrixTest, Scale) {
   Vector scale(num_cols);
   for (int i = 0; i < num_cols; ++i) {
     scale(i) = i + 1;
   }

   tsm->ScaleColumns(scale.data());
   crsm->ScaleColumns(scale.data());
   CompareMatrices(tsm.get(), crsm.get());
 }

 TEST_F(CompressedRowSparseMatrixTest, DeleteRows) {
   // Clear the row and column blocks as these are purely scalar tests.
   crsm->mutable_row_blocks()->clear();
   crsm->mutable_col_blocks()->clear();

   for (int i = 0; i < num_rows; ++i) {
     tsm->Resize(num_rows - i, num_cols);
     crsm->DeleteRows(crsm->num_rows() - tsm->num_rows());
     CompareMatrices(tsm.get(), crsm.get());
   }
 }

 TEST_F(CompressedRowSparseMatrixTest, AppendRows) {
   // Clear the row and column blocks as these are purely scalar tests.
   crsm->mutable_row_blocks()->clear();
   crsm->mutable_col_blocks()->clear();

   for (int i = 0; i < num_rows; ++i) {
     TripletSparseMatrix tsm_appendage(*tsm);
     tsm_appendage.Resize(i, num_cols);

     tsm->AppendRows(tsm_appendage);
     auto crsm_appendage =
         CompressedRowSparseMatrix::FromTripletSparseMatrix(tsm_appendage);

     crsm->AppendRows(*crsm_appendage);
     CompareMatrices(tsm.get(), crsm.get());
   }
 }

 TEST_F(CompressedRowSparseMatrixTest, AppendAndDeleteBlockDiagonalMatrix) {
   int num_diagonal_rows = crsm->num_cols();

   auto diagonal = std::make_unique<double[]>(num_diagonal_rows);
   for (int i = 0; i < num_diagonal_rows; ++i) {
     diagonal[i] = i;
   }

   std::vector<Block> row_and_column_blocks;
   row_and_column_blocks.emplace_back(1, 0);
   row_and_column_blocks.emplace_back(2, 1);
   row_and_column_blocks.emplace_back(2, 3);

   const std::vector<Block> pre_row_blocks = crsm->row_blocks();
   const std::vector<Block> pre_col_blocks = crsm->col_blocks();

   auto appendage = CompressedRowSparseMatrix::CreateBlockDiagonalMatrix(
       diagonal.get(), row_and_column_blocks);

   crsm->AppendRows(*appendage);

   const std::vector<Block> post_row_blocks = crsm->row_blocks();
   const std::vector<Block> post_col_blocks = crsm->col_blocks();

   std::vector<Block> expected_row_blocks = pre_row_blocks;
   expected_row_blocks.insert(expected_row_blocks.end(),
                              row_and_column_blocks.begin(),
                              row_and_column_blocks.end());

   std::vector<Block> expected_col_blocks = pre_col_blocks;

   EXPECT_EQ(expected_row_blocks, crsm->row_blocks());
   EXPECT_EQ(expected_col_blocks, crsm->col_blocks());

   crsm->DeleteRows(num_diagonal_rows);
   EXPECT_EQ(crsm->row_blocks(), pre_row_blocks);
   EXPECT_EQ(crsm->col_blocks(), pre_col_blocks);
 }

 TEST_F(CompressedRowSparseMatrixTest, ToDenseMatrix) {
   Matrix tsm_dense;
   Matrix crsm_dense;

   tsm->ToDenseMatrix(&tsm_dense);
   crsm->ToDenseMatrix(&crsm_dense);

   EXPECT_EQ((tsm_dense - crsm_dense).norm(), 0.0);
 }

 TEST_F(CompressedRowSparseMatrixTest, ToCRSMatrix) {
   CRSMatrix crs_matrix;
   crsm->ToCRSMatrix(&crs_matrix);
   EXPECT_EQ(crsm->num_rows(), crs_matrix.num_rows);
   EXPECT_EQ(crsm->num_cols(), crs_matrix.num_cols);
   EXPECT_EQ(crsm->num_rows() + 1, crs_matrix.rows.size());
   EXPECT_EQ(crsm->num_nonzeros(), crs_matrix.cols.size());
   EXPECT_EQ(crsm->num_nonzeros(), crs_matrix.values.size());

   for (int i = 0; i < crsm->num_rows() + 1; ++i) {
     EXPECT_EQ(crsm->rows()[i], crs_matrix.rows[i]);
   }

   for (int i = 0; i < crsm->num_nonzeros(); ++i) {
     EXPECT_EQ(crsm->cols()[i], crs_matrix.cols[i]);
     EXPECT_EQ(crsm->values()[i], crs_matrix.values[i]);
   }
 }

 TEST(CompressedRowSparseMatrix, CreateBlockDiagonalMatrix) {
   std::vector<Block> blocks;
   blocks.emplace_back(1, 0);
   blocks.emplace_back(2, 1);
   blocks.emplace_back(2, 3);

   Vector diagonal(5);
   for (int i = 0; i < 5; ++i) {
     diagonal(i) = i + 1;
   }

   auto matrix = CompressedRowSparseMatrix::CreateBlockDiagonalMatrix(
       diagonal.data(), blocks);

   EXPECT_EQ(matrix->num_rows(), 5);
   EXPECT_EQ(matrix->num_cols(), 5);
   EXPECT_EQ(matrix->num_nonzeros(), 9);
   EXPECT_EQ(blocks, matrix->row_blocks());
   EXPECT_EQ(blocks, matrix->col_blocks());

   Vector x(5);
   Vector y(5);

   x.setOnes();
   y.setZero();
   matrix->RightMultiplyAndAccumulate(x.data(), y.data());
   for (int i = 0; i < diagonal.size(); ++i) {
     EXPECT_EQ(y[i], diagonal[i]);
   }

   y.setZero();
   matrix->LeftMultiplyAndAccumulate(x.data(), y.data());
   for (int i = 0; i < diagonal.size(); ++i) {
     EXPECT_EQ(y[i], diagonal[i]);
   }

   Matrix dense;
   matrix->ToDenseMatrix(&dense);
   EXPECT_EQ((dense.diagonal() - diagonal).norm(), 0.0);
 }

 TEST(CompressedRowSparseMatrix, Transpose) {
   //  0  1  0  2  3  0
   //  4  6  7  0  0  8
   //  9 10  0 11 12  0
   // 13  0 14 15  9  0
   //  0 16 17  0  0  0

   // Block structure:
   //  A  A  A  A  B  B
   //  A  A  A  A  B  B
   //  A  A  A  A  B  B
   //  C  C  C  C  D  D
   //  C  C  C  C  D  D
   //  C  C  C  C  D  D

   CompressedRowSparseMatrix matrix(5, 6, 30);
   int* rows = matrix.mutable_rows();
   int* cols = matrix.mutable_cols();
   double* values = matrix.mutable_values();
   matrix.mutable_row_blocks()->emplace_back(3, 0);
   matrix.mutable_row_blocks()->emplace_back(3, 3);
   matrix.mutable_col_blocks()->emplace_back(4, 0);
   matrix.mutable_col_blocks()->emplace_back(2, 4);

   rows[0] = 0;
   cols[0] = 1;
   cols[1] = 3;
   cols[2] = 4;

   rows[1] = 3;
   cols[3] = 0;
   cols[4] = 1;
   cols[5] = 2;
   cols[6] = 5;

   rows[2] = 7;
   cols[7] = 0;
   cols[8] = 1;
   cols[9] = 3;
   cols[10] = 4;

   rows[3] = 11;
   cols[11] = 0;
   cols[12] = 2;
   cols[13] = 3;
   cols[14] = 4;

   rows[4] = 15;
   cols[15] = 1;
   cols[16] = 2;
   rows[5] = 17;

   std::copy(values, values + 17, cols);

   auto transpose = matrix.Transpose();

   ASSERT_EQ(transpose->row_blocks().size(), matrix.col_blocks().size());
   for (int i = 0; i < transpose->row_blocks().size(); ++i) {
     EXPECT_EQ(transpose->row_blocks()[i], matrix.col_blocks()[i]);
   }

   ASSERT_EQ(transpose->col_blocks().size(), matrix.row_blocks().size());
   for (int i = 0; i < transpose->col_blocks().size(); ++i) {
     EXPECT_EQ(transpose->col_blocks()[i], matrix.row_blocks()[i]);
   }

   Matrix dense_matrix;
   matrix.ToDenseMatrix(&dense_matrix);

   Matrix dense_transpose;
   transpose->ToDenseMatrix(&dense_transpose);
   EXPECT_NEAR((dense_matrix - dense_transpose.transpose()).norm(), 0.0, 1e-14);
 }

 TEST(CompressedRowSparseMatrix, FromTripletSparseMatrix) {
   std::mt19937 prng;
   TripletSparseMatrix::RandomMatrixOptions options;
   options.num_rows = 5;
   options.num_cols = 7;
   options.density = 0.5;

   const int kNumTrials = 10;
   for (int i = 0; i < kNumTrials; ++i) {
     auto tsm = TripletSparseMatrix::CreateRandomMatrix(options, prng);
     auto crsm = CompressedRowSparseMatrix::FromTripletSparseMatrix(*tsm);

     Matrix expected;
     tsm->ToDenseMatrix(&expected);
     Matrix actual;
     crsm->ToDenseMatrix(&actual);
     EXPECT_NEAR((expected - actual).norm() / actual.norm(),
                 0.0,
                 std::numeric_limits<double>::epsilon())
         << "\nexpected: \n"
         << expected << "\nactual: \n"
         << actual;
   }
 }

 TEST(CompressedRowSparseMatrix, FromTripletSparseMatrixTransposed) {
   std::mt19937 prng;
   TripletSparseMatrix::RandomMatrixOptions options;
   options.num_rows = 5;
   options.num_cols = 7;
   options.density = 0.5;

   const int kNumTrials = 10;
   for (int i = 0; i < kNumTrials; ++i) {
     auto tsm = TripletSparseMatrix::CreateRandomMatrix(options, prng);
     auto crsm =
         CompressedRowSparseMatrix::FromTripletSparseMatrixTransposed(*tsm);

     Matrix tmp;
     tsm->ToDenseMatrix(&tmp);
     Matrix expected = tmp.transpose();
     Matrix actual;
     crsm->ToDenseMatrix(&actual);
     EXPECT_NEAR((expected - actual).norm() / actual.norm(),
                 0.0,
                 std::numeric_limits<double>::epsilon())
         << "\nexpected: \n"
         << expected << "\nactual: \n"
         << actual;
   }
 }

 using Param = ::testing::tuple<CompressedRowSparseMatrix::StorageType>;

 static std::string ParamInfoToString(testing::TestParamInfo<Param> info) {
   if (::testing::get<0>(info.param) ==
       CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR) {
     return "UPPER";
   }

   if (::testing::get<0>(info.param) ==
       CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR) {
     return "LOWER";
   }

   return "UNSYMMETRIC";
 }

 class RightMultiplyAndAccumulateTest : public ::testing::TestWithParam<Param> {
 };

 TEST_P(RightMultiplyAndAccumulateTest, _) {
   const int kMinNumBlocks = 1;
   const int kMaxNumBlocks = 10;
   const int kMinBlockSize = 1;
   const int kMaxBlockSize = 5;
   const int kNumTrials = 10;
   std::mt19937 prng;
   std::uniform_real_distribution<double> uniform(0.5, 1.0);
   for (int num_blocks = kMinNumBlocks; num_blocks < kMaxNumBlocks;
        ++num_blocks) {
     for (int trial = 0; trial < kNumTrials; ++trial) {
       Param param = GetParam();
       CompressedRowSparseMatrix::RandomMatrixOptions options;
       options.num_col_blocks = num_blocks;
       options.min_col_block_size = kMinBlockSize;
       options.max_col_block_size = kMaxBlockSize;
       options.num_row_blocks = 2 * num_blocks;
       options.min_row_block_size = kMinBlockSize;
       options.max_row_block_size = kMaxBlockSize;
       options.block_density = uniform(prng);
       options.storage_type = ::testing::get<0>(param);
       auto matrix =
           CompressedRowSparseMatrix::CreateRandomMatrix(options, prng);
       const int num_rows = matrix->num_rows();
       const int num_cols = matrix->num_cols();

       Vector x(num_cols);
       x.setRandom();

       Vector actual_y(num_rows);
       actual_y.setZero();
       matrix->RightMultiplyAndAccumulate(x.data(), actual_y.data());

       Matrix dense;
       matrix->ToDenseMatrix(&dense);
       Vector expected_y;
       if (::testing::get<0>(param) ==
           CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR) {
         expected_y = dense.selfadjointView<Eigen::Upper>() * x;
       } else if (::testing::get<0>(param) ==
                  CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR) {
         expected_y = dense.selfadjointView<Eigen::Lower>() * x;
       } else {
         expected_y = dense * x;
       }

       ASSERT_NEAR((expected_y - actual_y).norm() / actual_y.norm(),
                   0.0,
                   std::numeric_limits<double>::epsilon() * 10)
           << "\n"
           << dense << "x:\n"
           << x.transpose() << "\n"
           << "expected: \n"
           << expected_y.transpose() << "\n"
           << "actual: \n"
           << actual_y.transpose();
     }
   }
 }

 INSTANTIATE_TEST_SUITE_P(
     CompressedRowSparseMatrix,
     RightMultiplyAndAccumulateTest,
     ::testing::Values(CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR,
                       CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR,
                       CompressedRowSparseMatrix::StorageType::UNSYMMETRIC),
     ParamInfoToString);

 class LeftMultiplyAndAccumulateTest : public ::testing::TestWithParam<Param> {};

 TEST_P(LeftMultiplyAndAccumulateTest, _) {
   const int kMinNumBlocks = 1;
   const int kMaxNumBlocks = 10;
   const int kMinBlockSize = 1;
   const int kMaxBlockSize = 5;
   const int kNumTrials = 10;
   std::mt19937 prng;
   std::uniform_real_distribution<double> uniform(0.5, 1.0);
   for (int num_blocks = kMinNumBlocks; num_blocks < kMaxNumBlocks;
        ++num_blocks) {
     for (int trial = 0; trial < kNumTrials; ++trial) {
       Param param = GetParam();
       CompressedRowSparseMatrix::RandomMatrixOptions options;
       options.num_col_blocks = num_blocks;
       options.min_col_block_size = kMinBlockSize;
       options.max_col_block_size = kMaxBlockSize;
       options.num_row_blocks = 2 * num_blocks;
       options.min_row_block_size = kMinBlockSize;
       options.max_row_block_size = kMaxBlockSize;
       options.block_density = uniform(prng);
       options.storage_type = ::testing::get<0>(param);
       auto matrix =
           CompressedRowSparseMatrix::CreateRandomMatrix(options, prng);
       const int num_rows = matrix->num_rows();
       const int num_cols = matrix->num_cols();

       Vector x(num_rows);
       x.setRandom();

       Vector actual_y(num_cols);
       actual_y.setZero();
       matrix->LeftMultiplyAndAccumulate(x.data(), actual_y.data());

       Matrix dense;
       matrix->ToDenseMatrix(&dense);
       Vector expected_y;
       if (::testing::get<0>(param) ==
           CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR) {
         expected_y = dense.selfadjointView<Eigen::Upper>() * x;
       } else if (::testing::get<0>(param) ==
                  CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR) {
         expected_y = dense.selfadjointView<Eigen::Lower>() * x;
       } else {
         expected_y = dense.transpose() * x;
       }

       ASSERT_NEAR((expected_y - actual_y).norm() / actual_y.norm(),
                   0.0,
                   std::numeric_limits<double>::epsilon() * 10)
           << "\n"
           << dense << "x\n"
           << x.transpose() << "\n"
           << "expected: \n"
           << expected_y.transpose() << "\n"
           << "actual: \n"
           << actual_y.transpose();
     }
   }
 }

 INSTANTIATE_TEST_SUITE_P(
     CompressedRowSparseMatrix,
     LeftMultiplyAndAccumulateTest,
     ::testing::Values(CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR,
                       CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR,
                       CompressedRowSparseMatrix::StorageType::UNSYMMETRIC),
     ParamInfoToString);

 class SquaredColumnNormTest : public ::testing::TestWithParam<Param> {};

 TEST_P(SquaredColumnNormTest, _) {
   const int kMinNumBlocks = 1;
   const int kMaxNumBlocks = 10;
   const int kMinBlockSize = 1;
   const int kMaxBlockSize = 5;
   const int kNumTrials = 10;
   std::mt19937 prng;
   std::uniform_real_distribution<double> uniform(0.5, 1.0);
   for (int num_blocks = kMinNumBlocks; num_blocks < kMaxNumBlocks;
        ++num_blocks) {
     for (int trial = 0; trial < kNumTrials; ++trial) {
       Param param = GetParam();
       CompressedRowSparseMatrix::RandomMatrixOptions options;
       options.num_col_blocks = num_blocks;
       options.min_col_block_size = kMinBlockSize;
       options.max_col_block_size = kMaxBlockSize;
       options.num_row_blocks = 2 * num_blocks;
       options.min_row_block_size = kMinBlockSize;
       options.max_row_block_size = kMaxBlockSize;
       options.block_density = uniform(prng);
       options.storage_type = ::testing::get<0>(param);
       auto matrix =
           CompressedRowSparseMatrix::CreateRandomMatrix(options, prng);
       const int num_cols = matrix->num_cols();

       Vector actual(num_cols);
       actual.setZero();
       matrix->SquaredColumnNorm(actual.data());

       Matrix dense;
       matrix->ToDenseMatrix(&dense);
       Vector expected;
       if (::testing::get<0>(param) ==
           CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR) {
         const Matrix full = dense.selfadjointView<Eigen::Upper>();
         expected = full.colwise().squaredNorm();
       } else if (::testing::get<0>(param) ==
                  CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR) {
         const Matrix full = dense.selfadjointView<Eigen::Lower>();
         expected = full.colwise().squaredNorm();
       } else {
         expected = dense.colwise().squaredNorm();
       }

       ASSERT_NEAR((expected - actual).norm() / actual.norm(),
                   0.0,
                   std::numeric_limits<double>::epsilon() * 10)
           << "\n"
           << dense << "expected: \n"
           << expected.transpose() << "\n"
           << "actual: \n"
           << actual.transpose();
     }
   }
 }

 INSTANTIATE_TEST_SUITE_P(
     CompressedRowSparseMatrix,
     SquaredColumnNormTest,
     ::testing::Values(CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR,
                       CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR,
                       CompressedRowSparseMatrix::StorageType::UNSYMMETRIC),
     ParamInfoToString);

 // TODO(sameeragarwal) Add tests for the random matrix creation methods.

 }  // namespace ceres::internal
	// Ceres Solver - A fast non-linear least squares minimizer
	// Copyright 2022 Google Inc. All rights reserved.
	// http://ceres-solver.org/
	//
	// Redistribution and use in source and binary forms, with or without
	// modification, are permitted provided that the following conditions are met:
	//
	// * Redistributions of source code must retain the above copyright notice,
	// this list of conditions and the following disclaimer.
	// * Redistributions in binary form must reproduce the above copyright notice,
	// this list of conditions and the following disclaimer in the documentation
	// and/or other materials provided with the distribution.
	// * Neither the name of Google Inc. nor the names of its contributors may be
	// used to endorse or promote products derived from this software without
	// specific prior written permission.
	//
	// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	// POSSIBILITY OF SUCH DAMAGE.
	//
	// Author: sameeragarwal@google.com (Sameer Agarwal)

	#include "ceres/compressed_row_sparse_matrix.h"

	#include <algorithm>
	#include <memory>
	#include <numeric>
	#include <random>
	#include <string>
	#include <vector>

	#include "Eigen/SparseCore"
	#include "ceres/casts.h"
	#include "ceres/crs_matrix.h"
	#include "ceres/internal/eigen.h"
	#include "ceres/linear_least_squares_problems.h"
	#include "ceres/triplet_sparse_matrix.h"
	#include "glog/logging.h"
	#include "gtest/gtest.h"

	namespace ceres::internal {

	static void CompareMatrices(const SparseMatrix* a, const SparseMatrix* b) {
	EXPECT_EQ(a->num_rows(), b->num_rows());
	EXPECT_EQ(a->num_cols(), b->num_cols());

	int num_rows = a->num_rows();
	int num_cols = a->num_cols();

	for (int i = 0; i < num_cols; ++i) {
	Vector x = Vector::Zero(num_cols);
	x(i) = 1.0;

	Vector y_a = Vector::Zero(num_rows);
	Vector y_b = Vector::Zero(num_rows);

	a->RightMultiplyAndAccumulate(x.data(), y_a.data());
	b->RightMultiplyAndAccumulate(x.data(), y_b.data());
	EXPECT_EQ((y_a - y_b).norm(), 0);
	}
	}

	class CompressedRowSparseMatrixTest : public ::testing::Test {
	protected:
	void SetUp() final {
	auto problem = CreateLinearLeastSquaresProblemFromId(1);

	CHECK(problem != nullptr);

	tsm.reset(down_cast<TripletSparseMatrix*>(problem->A.release()));
	crsm = CompressedRowSparseMatrix::FromTripletSparseMatrix(*tsm);

	num_rows = tsm->num_rows();
	num_cols = tsm->num_cols();

	std::vector<Block>* row_blocks = crsm->mutable_row_blocks();
	row_blocks->resize(num_rows);
	for (int i = 0; i < row_blocks->size(); ++i) {
	(*row_blocks)[i] = Block(1, i);
	}
	std::vector<Block>* col_blocks = crsm->mutable_col_blocks();
	col_blocks->resize(num_cols);
	for (int i = 0; i < col_blocks->size(); ++i) {
	(*col_blocks)[i] = Block(1, i);
	}
	}

	int num_rows;
	int num_cols;

	std::unique_ptr<TripletSparseMatrix> tsm;
	std::unique_ptr<CompressedRowSparseMatrix> crsm;
	};

	TEST_F(CompressedRowSparseMatrixTest, Scale) {
	Vector scale(num_cols);
	for (int i = 0; i < num_cols; ++i) {
	scale(i) = i + 1;
	}

	tsm->ScaleColumns(scale.data());
	crsm->ScaleColumns(scale.data());
	CompareMatrices(tsm.get(), crsm.get());
	}

	TEST_F(CompressedRowSparseMatrixTest, DeleteRows) {
	// Clear the row and column blocks as these are purely scalar tests.
	crsm->mutable_row_blocks()->clear();
	crsm->mutable_col_blocks()->clear();

	for (int i = 0; i < num_rows; ++i) {
	tsm->Resize(num_rows - i, num_cols);
	crsm->DeleteRows(crsm->num_rows() - tsm->num_rows());
	CompareMatrices(tsm.get(), crsm.get());
	}
	}

	TEST_F(CompressedRowSparseMatrixTest, AppendRows) {
	// Clear the row and column blocks as these are purely scalar tests.
	crsm->mutable_row_blocks()->clear();
	crsm->mutable_col_blocks()->clear();

	for (int i = 0; i < num_rows; ++i) {
	TripletSparseMatrix tsm_appendage(*tsm);
	tsm_appendage.Resize(i, num_cols);

	tsm->AppendRows(tsm_appendage);
	auto crsm_appendage =
	CompressedRowSparseMatrix::FromTripletSparseMatrix(tsm_appendage);

	crsm->AppendRows(*crsm_appendage);
	CompareMatrices(tsm.get(), crsm.get());
	}
	}

	TEST_F(CompressedRowSparseMatrixTest, AppendAndDeleteBlockDiagonalMatrix) {
	int num_diagonal_rows = crsm->num_cols();

	auto diagonal = std::make_unique<double[]>(num_diagonal_rows);
	for (int i = 0; i < num_diagonal_rows; ++i) {
	diagonal[i] = i;
	}

	std::vector<Block> row_and_column_blocks;
	row_and_column_blocks.emplace_back(1, 0);
	row_and_column_blocks.emplace_back(2, 1);
	row_and_column_blocks.emplace_back(2, 3);

	const std::vector<Block> pre_row_blocks = crsm->row_blocks();
	const std::vector<Block> pre_col_blocks = crsm->col_blocks();

	auto appendage = CompressedRowSparseMatrix::CreateBlockDiagonalMatrix(
	diagonal.get(), row_and_column_blocks);

	crsm->AppendRows(*appendage);

	const std::vector<Block> post_row_blocks = crsm->row_blocks();
	const std::vector<Block> post_col_blocks = crsm->col_blocks();

	std::vector<Block> expected_row_blocks = pre_row_blocks;
	expected_row_blocks.insert(expected_row_blocks.end(),
	row_and_column_blocks.begin(),
	row_and_column_blocks.end());

	std::vector<Block> expected_col_blocks = pre_col_blocks;

	EXPECT_EQ(expected_row_blocks, crsm->row_blocks());
	EXPECT_EQ(expected_col_blocks, crsm->col_blocks());

	crsm->DeleteRows(num_diagonal_rows);
	EXPECT_EQ(crsm->row_blocks(), pre_row_blocks);
	EXPECT_EQ(crsm->col_blocks(), pre_col_blocks);
	}

	TEST_F(CompressedRowSparseMatrixTest, ToDenseMatrix) {
	Matrix tsm_dense;
	Matrix crsm_dense;

	tsm->ToDenseMatrix(&tsm_dense);
	crsm->ToDenseMatrix(&crsm_dense);

	EXPECT_EQ((tsm_dense - crsm_dense).norm(), 0.0);
	}

	TEST_F(CompressedRowSparseMatrixTest, ToCRSMatrix) {
	CRSMatrix crs_matrix;
	crsm->ToCRSMatrix(&crs_matrix);
	EXPECT_EQ(crsm->num_rows(), crs_matrix.num_rows);
	EXPECT_EQ(crsm->num_cols(), crs_matrix.num_cols);
	EXPECT_EQ(crsm->num_rows() + 1, crs_matrix.rows.size());
	EXPECT_EQ(crsm->num_nonzeros(), crs_matrix.cols.size());
	EXPECT_EQ(crsm->num_nonzeros(), crs_matrix.values.size());

	for (int i = 0; i < crsm->num_rows() + 1; ++i) {
	EXPECT_EQ(crsm->rows()[i], crs_matrix.rows[i]);
	}

	for (int i = 0; i < crsm->num_nonzeros(); ++i) {
	EXPECT_EQ(crsm->cols()[i], crs_matrix.cols[i]);
	EXPECT_EQ(crsm->values()[i], crs_matrix.values[i]);
	}
	}

	TEST(CompressedRowSparseMatrix, CreateBlockDiagonalMatrix) {
	std::vector<Block> blocks;
	blocks.emplace_back(1, 0);
	blocks.emplace_back(2, 1);
	blocks.emplace_back(2, 3);

	Vector diagonal(5);
	for (int i = 0; i < 5; ++i) {
	diagonal(i) = i + 1;
	}

	auto matrix = CompressedRowSparseMatrix::CreateBlockDiagonalMatrix(
	diagonal.data(), blocks);

	EXPECT_EQ(matrix->num_rows(), 5);
	EXPECT_EQ(matrix->num_cols(), 5);
	EXPECT_EQ(matrix->num_nonzeros(), 9);
	EXPECT_EQ(blocks, matrix->row_blocks());
	EXPECT_EQ(blocks, matrix->col_blocks());

	Vector x(5);
	Vector y(5);

	x.setOnes();
	y.setZero();
	matrix->RightMultiplyAndAccumulate(x.data(), y.data());
	for (int i = 0; i < diagonal.size(); ++i) {
	EXPECT_EQ(y[i], diagonal[i]);
	}

	y.setZero();
	matrix->LeftMultiplyAndAccumulate(x.data(), y.data());
	for (int i = 0; i < diagonal.size(); ++i) {
	EXPECT_EQ(y[i], diagonal[i]);
	}

	Matrix dense;
	matrix->ToDenseMatrix(&dense);
	EXPECT_EQ((dense.diagonal() - diagonal).norm(), 0.0);
	}

	TEST(CompressedRowSparseMatrix, Transpose) {
	// 0 1 0 2 3 0
	// 4 6 7 0 0 8
	// 9 10 0 11 12 0
	// 13 0 14 15 9 0
	// 0 16 17 0 0 0

	// Block structure:
	// A A A A B B
	// A A A A B B
	// A A A A B B
	// C C C C D D
	// C C C C D D
	// C C C C D D

	CompressedRowSparseMatrix matrix(5, 6, 30);
	int* rows = matrix.mutable_rows();
	int* cols = matrix.mutable_cols();
	double* values = matrix.mutable_values();
	matrix.mutable_row_blocks()->emplace_back(3, 0);
	matrix.mutable_row_blocks()->emplace_back(3, 3);
	matrix.mutable_col_blocks()->emplace_back(4, 0);
	matrix.mutable_col_blocks()->emplace_back(2, 4);

	rows[0] = 0;
	cols[0] = 1;
	cols[1] = 3;
	cols[2] = 4;

	rows[1] = 3;
	cols[3] = 0;
	cols[4] = 1;
	cols[5] = 2;
	cols[6] = 5;

	rows[2] = 7;
	cols[7] = 0;
	cols[8] = 1;
	cols[9] = 3;
	cols[10] = 4;

	rows[3] = 11;
	cols[11] = 0;
	cols[12] = 2;
	cols[13] = 3;
	cols[14] = 4;

	rows[4] = 15;
	cols[15] = 1;
	cols[16] = 2;
	rows[5] = 17;

	std::copy(values, values + 17, cols);

	auto transpose = matrix.Transpose();

	ASSERT_EQ(transpose->row_blocks().size(), matrix.col_blocks().size());
	for (int i = 0; i < transpose->row_blocks().size(); ++i) {
	EXPECT_EQ(transpose->row_blocks()[i], matrix.col_blocks()[i]);
	}

	ASSERT_EQ(transpose->col_blocks().size(), matrix.row_blocks().size());
	for (int i = 0; i < transpose->col_blocks().size(); ++i) {
	EXPECT_EQ(transpose->col_blocks()[i], matrix.row_blocks()[i]);
	}

	Matrix dense_matrix;
	matrix.ToDenseMatrix(&dense_matrix);

	Matrix dense_transpose;
	transpose->ToDenseMatrix(&dense_transpose);
	EXPECT_NEAR((dense_matrix - dense_transpose.transpose()).norm(), 0.0, 1e-14);
	}

	TEST(CompressedRowSparseMatrix, FromTripletSparseMatrix) {
	std::mt19937 prng;
	TripletSparseMatrix::RandomMatrixOptions options;
	options.num_rows = 5;
	options.num_cols = 7;
	options.density = 0.5;

	const int kNumTrials = 10;
	for (int i = 0; i < kNumTrials; ++i) {
	auto tsm = TripletSparseMatrix::CreateRandomMatrix(options, prng);
	auto crsm = CompressedRowSparseMatrix::FromTripletSparseMatrix(*tsm);

	Matrix expected;
	tsm->ToDenseMatrix(&expected);
	Matrix actual;
	crsm->ToDenseMatrix(&actual);
	EXPECT_NEAR((expected - actual).norm() / actual.norm(),
	0.0,
	std::numeric_limits<double>::epsilon())
	<< "\nexpected: \n"
	<< expected << "\nactual: \n"
	<< actual;
	}
	}

	TEST(CompressedRowSparseMatrix, FromTripletSparseMatrixTransposed) {
	std::mt19937 prng;
	TripletSparseMatrix::RandomMatrixOptions options;
	options.num_rows = 5;
	options.num_cols = 7;
	options.density = 0.5;

	const int kNumTrials = 10;
	for (int i = 0; i < kNumTrials; ++i) {
	auto tsm = TripletSparseMatrix::CreateRandomMatrix(options, prng);
	auto crsm =
	CompressedRowSparseMatrix::FromTripletSparseMatrixTransposed(*tsm);

	Matrix tmp;
	tsm->ToDenseMatrix(&tmp);
	Matrix expected = tmp.transpose();
	Matrix actual;
	crsm->ToDenseMatrix(&actual);
	EXPECT_NEAR((expected - actual).norm() / actual.norm(),
	0.0,
	std::numeric_limits<double>::epsilon())
	<< "\nexpected: \n"
	<< expected << "\nactual: \n"
	<< actual;
	}
	}

	using Param = ::testing::tuple<CompressedRowSparseMatrix::StorageType>;

	static std::string ParamInfoToString(testing::TestParamInfo<Param> info) {
	if (::testing::get<0>(info.param) ==
	CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR) {
	return "UPPER";
	}

	if (::testing::get<0>(info.param) ==
	CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR) {
	return "LOWER";
	}

	return "UNSYMMETRIC";
	}

	class RightMultiplyAndAccumulateTest : public ::testing::TestWithParam<Param> {
	};

	TEST_P(RightMultiplyAndAccumulateTest, _) {
	const int kMinNumBlocks = 1;
	const int kMaxNumBlocks = 10;
	const int kMinBlockSize = 1;
	const int kMaxBlockSize = 5;
	const int kNumTrials = 10;
	std::mt19937 prng;
	std::uniform_real_distribution<double> uniform(0.5, 1.0);
	for (int num_blocks = kMinNumBlocks; num_blocks < kMaxNumBlocks;
	++num_blocks) {
	for (int trial = 0; trial < kNumTrials; ++trial) {
	Param param = GetParam();
	CompressedRowSparseMatrix::RandomMatrixOptions options;
	options.num_col_blocks = num_blocks;
	options.min_col_block_size = kMinBlockSize;
	options.max_col_block_size = kMaxBlockSize;
	options.num_row_blocks = 2 * num_blocks;
	options.min_row_block_size = kMinBlockSize;
	options.max_row_block_size = kMaxBlockSize;
	options.block_density = uniform(prng);
	options.storage_type = ::testing::get<0>(param);
	auto matrix =
	CompressedRowSparseMatrix::CreateRandomMatrix(options, prng);
	const int num_rows = matrix->num_rows();
	const int num_cols = matrix->num_cols();

	Vector x(num_cols);
	x.setRandom();

	Vector actual_y(num_rows);
	actual_y.setZero();
	matrix->RightMultiplyAndAccumulate(x.data(), actual_y.data());

	Matrix dense;
	matrix->ToDenseMatrix(&dense);
	Vector expected_y;
	if (::testing::get<0>(param) ==
	CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR) {
	expected_y = dense.selfadjointView<Eigen::Upper>() * x;
	} else if (::testing::get<0>(param) ==
	CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR) {
	expected_y = dense.selfadjointView<Eigen::Lower>() * x;
	} else {
	expected_y = dense * x;
	}

	ASSERT_NEAR((expected_y - actual_y).norm() / actual_y.norm(),
	0.0,
	std::numeric_limits<double>::epsilon() * 10)
	<< "\n"
	<< dense << "x:\n"
	<< x.transpose() << "\n"
	<< "expected: \n"
	<< expected_y.transpose() << "\n"
	<< "actual: \n"
	<< actual_y.transpose();
	}
	}
	}

	INSTANTIATE_TEST_SUITE_P(
	CompressedRowSparseMatrix,
	RightMultiplyAndAccumulateTest,
	::testing::Values(CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR,
	CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR,
	CompressedRowSparseMatrix::StorageType::UNSYMMETRIC),
	ParamInfoToString);

	class LeftMultiplyAndAccumulateTest : public ::testing::TestWithParam<Param> {};

	TEST_P(LeftMultiplyAndAccumulateTest, _) {
	const int kMinNumBlocks = 1;
	const int kMaxNumBlocks = 10;
	const int kMinBlockSize = 1;
	const int kMaxBlockSize = 5;
	const int kNumTrials = 10;
	std::mt19937 prng;
	std::uniform_real_distribution<double> uniform(0.5, 1.0);
	for (int num_blocks = kMinNumBlocks; num_blocks < kMaxNumBlocks;
	++num_blocks) {
	for (int trial = 0; trial < kNumTrials; ++trial) {
	Param param = GetParam();
	CompressedRowSparseMatrix::RandomMatrixOptions options;
	options.num_col_blocks = num_blocks;
	options.min_col_block_size = kMinBlockSize;
	options.max_col_block_size = kMaxBlockSize;
	options.num_row_blocks = 2 * num_blocks;
	options.min_row_block_size = kMinBlockSize;
	options.max_row_block_size = kMaxBlockSize;
	options.block_density = uniform(prng);
	options.storage_type = ::testing::get<0>(param);
	auto matrix =
	CompressedRowSparseMatrix::CreateRandomMatrix(options, prng);
	const int num_rows = matrix->num_rows();
	const int num_cols = matrix->num_cols();

	Vector x(num_rows);
	x.setRandom();

	Vector actual_y(num_cols);
	actual_y.setZero();
	matrix->LeftMultiplyAndAccumulate(x.data(), actual_y.data());

	Matrix dense;
	matrix->ToDenseMatrix(&dense);
	Vector expected_y;
	if (::testing::get<0>(param) ==
	CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR) {
	expected_y = dense.selfadjointView<Eigen::Upper>() * x;
	} else if (::testing::get<0>(param) ==
	CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR) {
	expected_y = dense.selfadjointView<Eigen::Lower>() * x;
	} else {
	expected_y = dense.transpose() * x;
	}

	ASSERT_NEAR((expected_y - actual_y).norm() / actual_y.norm(),
	0.0,
	std::numeric_limits<double>::epsilon() * 10)
	<< "\n"
	<< dense << "x\n"
	<< x.transpose() << "\n"
	<< "expected: \n"
	<< expected_y.transpose() << "\n"
	<< "actual: \n"
	<< actual_y.transpose();
	}
	}
	}

	INSTANTIATE_TEST_SUITE_P(
	CompressedRowSparseMatrix,
	LeftMultiplyAndAccumulateTest,
	::testing::Values(CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR,
	CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR,
	CompressedRowSparseMatrix::StorageType::UNSYMMETRIC),
	ParamInfoToString);

	class SquaredColumnNormTest : public ::testing::TestWithParam<Param> {};

	TEST_P(SquaredColumnNormTest, _) {
	const int kMinNumBlocks = 1;
	const int kMaxNumBlocks = 10;
	const int kMinBlockSize = 1;
	const int kMaxBlockSize = 5;
	const int kNumTrials = 10;
	std::mt19937 prng;
	std::uniform_real_distribution<double> uniform(0.5, 1.0);
	for (int num_blocks = kMinNumBlocks; num_blocks < kMaxNumBlocks;
	++num_blocks) {
	for (int trial = 0; trial < kNumTrials; ++trial) {
	Param param = GetParam();
	CompressedRowSparseMatrix::RandomMatrixOptions options;
	options.num_col_blocks = num_blocks;
	options.min_col_block_size = kMinBlockSize;
	options.max_col_block_size = kMaxBlockSize;
	options.num_row_blocks = 2 * num_blocks;
	options.min_row_block_size = kMinBlockSize;
	options.max_row_block_size = kMaxBlockSize;
	options.block_density = uniform(prng);
	options.storage_type = ::testing::get<0>(param);
	auto matrix =
	CompressedRowSparseMatrix::CreateRandomMatrix(options, prng);
	const int num_cols = matrix->num_cols();

	Vector actual(num_cols);
	actual.setZero();
	matrix->SquaredColumnNorm(actual.data());

	Matrix dense;
	matrix->ToDenseMatrix(&dense);
	Vector expected;
	if (::testing::get<0>(param) ==
	CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR) {
	const Matrix full = dense.selfadjointView<Eigen::Upper>();
	expected = full.colwise().squaredNorm();
	} else if (::testing::get<0>(param) ==
	CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR) {
	const Matrix full = dense.selfadjointView<Eigen::Lower>();
	expected = full.colwise().squaredNorm();
	} else {
	expected = dense.colwise().squaredNorm();
	}

	ASSERT_NEAR((expected - actual).norm() / actual.norm(),
	0.0,
	std::numeric_limits<double>::epsilon() * 10)
	<< "\n"
	<< dense << "expected: \n"
	<< expected.transpose() << "\n"
	<< "actual: \n"
	<< actual.transpose();
	}
	}
	}

	INSTANTIATE_TEST_SUITE_P(
	CompressedRowSparseMatrix,
	SquaredColumnNormTest,
	::testing::Values(CompressedRowSparseMatrix::StorageType::LOWER_TRIANGULAR,
	CompressedRowSparseMatrix::StorageType::UPPER_TRIANGULAR,
	CompressedRowSparseMatrix::StorageType::UNSYMMETRIC),
	ParamInfoToString);

	// TODO(sameeragarwal) Add tests for the random matrix creation methods.

	} // namespace ceres::internal