// 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)

#include "ceres/normal_prior.h"

#include <cstddef>

#include <vector>

#include "ceres/internal/eigen.h"

#include "ceres/internal/scoped_ptr.h"

#include "ceres/types.h"

#include "glog/logging.h"

namespace ceres {

NormalPrior::NormalPrior(const Matrix& A, const Vector& b)

    : A_(A), b_(b) {

  CHECK_GT(b_.rows(), 0);

  CHECK_GT(A_.rows(), 0);

  CHECK_EQ(b_.rows(), A.cols());

  set_num_residuals(A_.rows());

  mutable_parameter_block_sizes()->push_back(b_.rows());

}

bool NormalPrior::Evaluate(double const* const* parameters,

                           double* residuals,

                           double** jacobians) const {

  ConstVectorRef p(parameters[0], parameter_block_sizes()[0]);

  VectorRef r(residuals, num_residuals());

  // The following line should read

  // r = A_ * (p - b_);

  // The extra eval is to get around a bug in the eigen library.

  r = A_ * (p - b_).eval();

  if ((jacobians != NULL) && (jacobians[0] != NULL)) {

    MatrixRef(jacobians[0], num_residuals(), parameter_block_sizes()[0]) = A_;

  }

  return true;

}

}  // namespace ceres