include/ceres/crs_matrix.h

// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2012 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
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// modification, are permitted provided that the following conditions are met:
//
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// Author: sameeragarwal@google.com (Sameer Agarwal)

#ifndef CERES_PUBLIC_CRS_MATRIX_H_
#define CERES_PUBLIC_CRS_MATRIX_H_

#include <vector>
#include "ceres/internal/port.h"

namespace ceres {

// A compressed row sparse matrix used primarily for communicating the
// Jacobian matrix to the user.
struct CRSMatrix {
  CRSMatrix() : num_rows(0), num_cols(0) {}

  int num_rows;
  int num_cols;

  // A compressed row matrix stores its contents in three arrays.
  // The non-zero pattern of the i^th row is given by
  //
  //   rows[cols[i] ... cols[i + 1]]
  //
  // and the corresponding values by
  //
  //   values[cols[i] ... cols[i + 1]]
  //
  // Thus, cols is a vector of size num_cols + 1, and rows and values
  // have as many entries as number of non-zeros in the matrix.
  vector<int> cols;
  vector<int> rows;
  vector<double> values;
};

}  // namespace ceres

#endif  // CERES_PUBLIC_CRS_MATRIX_H_