// 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: sameeragarwal@google.com (Sameer Agarwal)

//

// Base classes for access to an linear operator.

#ifndef CERES_INTERNAL_LINEAR_OPERATOR_H_

#define CERES_INTERNAL_LINEAR_OPERATOR_H_

#include "ceres/types.h"

namespace ceres {

namespace internal {

// This is an abstract base class for linear operators. It supports

// access to size information and left and right multiply operators.

class LinearOperator {

 public:

  virtual ~LinearOperator();

  // y = y + Ax;

  virtual void RightMultiply(const double* x, double* y) const = 0;

  // y = y + A'x;

  virtual void LeftMultiply(const double* x, double* y) const = 0;

  virtual int num_rows() const = 0;

  virtual int num_cols() const = 0;

};

}  // namespace internal

}  // namespace ceres

#endif  // CERES_INTERNAL_LINEAR_OPERATOR_H_