// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2015 Google Inc. All rights reserved.
// http://ceres-solver.org/
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// Author: keir@google.com (Keir Mierle)

#include "ceres/dense_sparse_matrix.h"

#include <algorithm>

#include "ceres/internal/eigen.h"
#include "ceres/internal/port.h"
#include "ceres/triplet_sparse_matrix.h"
#include "glog/logging.h"

namespace ceres {
namespace internal {

DenseSparseMatrix::DenseSparseMatrix(int num_rows, int num_cols)
    : m_(Matrix(num_rows, num_cols)) {}

DenseSparseMatrix::DenseSparseMatrix(const TripletSparseMatrix& m)
    : m_(Matrix::Zero(m.num_rows(), m.num_cols())) {
  const double* values = m.values();
  const int* rows = m.rows();
  const int* cols = m.cols();
  int num_nonzeros = m.num_nonzeros();

  for (int i = 0; i < num_nonzeros; ++i) {
    m_(rows[i], cols[i]) += values[i];
  }
}

DenseSparseMatrix::DenseSparseMatrix(const Matrix& m) : m_(m) {}

void DenseSparseMatrix::SetZero() { m_.setZero(); }

void DenseSparseMatrix::RightMultiply(const double* x, double* y) const {
  VectorRef(y, num_rows()) += matrix() * ConstVectorRef(x, num_cols());
}

void DenseSparseMatrix::LeftMultiply(const double* x, double* y) const {
  VectorRef(y, num_cols()) +=
      matrix().transpose() * ConstVectorRef(x, num_rows());
}

void DenseSparseMatrix::SquaredColumnNorm(double* x) const {
  VectorRef(x, num_cols()) = m_.colwise().squaredNorm();
}

void DenseSparseMatrix::ScaleColumns(const double* scale) {
  m_ *= ConstVectorRef(scale, num_cols()).asDiagonal();
}

void DenseSparseMatrix::ToDenseMatrix(Matrix* dense_matrix) const {
  *dense_matrix = m_;
}

int DenseSparseMatrix::num_rows() const { return m_.rows(); }

int DenseSparseMatrix::num_cols() const { return m_.cols(); }

int DenseSparseMatrix::num_nonzeros() const { return m_.rows() * m_.cols(); }

const Matrix& DenseSparseMatrix::matrix() const { return m_; }

Matrix* DenseSparseMatrix::mutable_matrix() { return &m_; }

void DenseSparseMatrix::ToTextFile(FILE* file) const {
  CHECK(file != nullptr);
  for (int r = 0; r < m_.rows(); ++r) {
    for (int c = 0; c < m_.cols(); ++c) {
      fprintf(file, "% 10d % 10d %17f\n", r, c, m_(r, c));
    }
  }
}

}  // namespace internal
}  // namespace ceres