/*
 * Copyright (C) 2005-2020 Centre National d'Etudes Spatiales (CNES)
 *
 * This file is part of Orfeo Toolbox
 *
 *     https://www.orfeo-toolbox.org/
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef otbTimeSeries_h
#define otbTimeSeries_h

#include "itkFixedArray.h"
#include <cmath>

namespace otb
{
template <unsigned int TDegree = 2, class TCoefPrecision = double>
class PolynomialTimeSeries
{
public:
  typedef TCoefPrecision CoefficientsPrecisionType;
  typedef itk::FixedArray<CoefficientsPrecisionType, TDegree + 1> CoefficientsType;


  /// Constructor
  PolynomialTimeSeries()
  {
  }
  /// Destructor
  virtual ~PolynomialTimeSeries()
  {
  }

  inline void SetCoefficients(CoefficientsType& coeffs)
  {
    for (unsigned int i = 0; i <= TDegree; ++i)
      m_Coefficients[i] = coeffs[i];
  }

  inline TCoefPrecision GetCoefficient(unsigned int co) const
  {
    return m_Coefficients[co];
  }

  inline CoefficientsType GetCoefficients() const
  {
    return m_Coefficients;
  }

  inline CoefficientsPrecisionType GetValue(CoefficientsPrecisionType val) const
  {
    CoefficientsPrecisionType tmpVal = 0;
    for (unsigned int i = 0; i <= TDegree; ++i)
      tmpVal += m_Coefficients[i] * std::pow(val, static_cast<CoefficientsPrecisionType>(i));
    return tmpVal;
  }

private:
  CoefficientsType m_Coefficients;
};
}
#endif
