// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2010, 2011, 2012 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
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// Author: keir@google.com (Keir Mierle)

#include "ceres/levenberg_marquardt.h"

#include "gtest/gtest.h"

namespace ceres2 {
namespace internal {

class PowellEvaluator : public Evaluator {
 public:
  PowellEvaluator(const Program& program);
  virtual ~PowellEvaluator() {}

  // Implementation of Evaluator interface.
  virtual SparseMatrix* CreateJacobian() const {
    DenseSparseMatrix* dense_jacobian =
        new DenseSparseMatrix(NumResiduals(), NumEffectiveParameters());
    dense_jacobian->SetZero();
    return dense_jacobian;
  }

  virtual bool Evaluate(const double* state,
                        double* cost,
                        double* residuals,
                        SparseMatrix* jacobian) {

    // f1 = x1 + 10 * x2;
    double r0 = x1[0] + T(10.0) * x2[0];
    // f2 = sqrt(5) (x3 - x4)
    double r1 = T(sqrt(5.0)) * (x3[0] - x4[0]);
    // f3 = (x2 - 2 x3)^2
    double r2 = (x2[0] - T(2.0) * x4[0]) * (x2[0] - T(2.0) * x4[0]);
    // f4 = sqrt(10) (x1 - x4)^2
    double r3 = T(sqrt(10.0)) * (x1[0] - x4[0]) * (x1[0] - x4[0]);

    if (residuals != NULL) {
      residuals[0] = r0;

    if (jacobian == 
    AlignedMatrixRef jacobian 
  }

  virtual bool Plus(const double* state,
                    const double* delta,
                    double* state_plus_delta) const;
  virtual int NumEffectiveParameters() const;
  virtual int NumParameters() const;
  virtual int NumResiduals() const;
};


}  // namespace internal
}  // namespace ceres2