/***************************************************************************
 *                   GIntegral.hpp - Integration class                     *
 * ----------------------------------------------------------------------- *
 *  copyright (C) 2010-2013 by Juergen Knoedlseder                         *
 * ----------------------------------------------------------------------- *
 *                                                                         *
 *  This program is free software: you can redistribute it and/or modify   *
 *  it under the terms of the GNU General Public License as published by   *
 *  the Free Software Foundation, either version 3 of the License, or      *
 *  (at your option) any later version.                                    *
 *                                                                         *
 *  This program is distributed in the hope that it will be useful,        *
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of         *
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the          *
 *  GNU General Public License for more details.                           *
 *                                                                         *
 *  You should have received a copy of the GNU General Public License      *
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.  *
 *                                                                         *
 ***************************************************************************/
/**
 * @file GIntegral.hpp
 * @brief Integration class interface definition
 * @author Juergen Knoedlseder
 */

#ifndef GINTEGRAL_HPP
#define GINTEGRAL_HPP

/* __ Includes ___________________________________________________________ */
#include <string>
#include "GBase.hpp"
#include "GFunction.hpp"


/***********************************************************************//**
 * @class GIntegral
 *
 * @brief GIntegral class interface definition.
 *
 * This class allows to perform integration using various methods. The
 * integrand is implemented by a derived class of GIntegrand.
 ***************************************************************************/
class GIntegral : public GBase {

public:

    // Constructors and destructors
    explicit GIntegral(void);
    explicit GIntegral(GFunction* kernel);
    GIntegral(const GIntegral& integral);
    virtual ~GIntegral(void);

    // Operators
    GIntegral& operator=(const GIntegral& integral);

    // Methods
    void             clear(void);
    GIntegral*       clone(void) const;
    void             max_iter(const int& max_iter);
    void             eps(const double& eps);
    void             silent(const bool& silent);
    const int&       iter(void) const;
    const int&       max_iter(void) const;
    const double&    eps(void) const;
    const bool&      silent(void) const;
    void             kernel(GFunction* kernel);
    const GFunction* kernel(void) const;
    double           romb(const double& a, const double& b, const int& k = 5);
    double           trapzd(const double& a, const double& b, const int& n = 1,
                            double result = 0.0);
    std::string      print(const GChatter& chatter = NORMAL) const;

protected:
    // Protected methods
    void   init_members(void);
    void   copy_members(const GIntegral& integral);
    void   free_members(void);
    double polint(double* xa, double* ya, int n, double x, double *dy);

    // Protected data area
    GFunction* m_kernel;       //!< Pointer to function kernel
    double     m_eps;          //!< Integration precision
    int        m_max_iter;     //!< Maximum number of iterations
    int        m_iter;         //!< Number of iterations used
    bool       m_silent;       //!< Suppress integration warnings
};


/***********************************************************************//**
 * @brief Return number of iterations
 *
 * @return Number of iterations.
 ***************************************************************************/
inline
const int& GIntegral::iter(void) const
{
    return m_iter;
}


/***********************************************************************//**
 * @brief Set maximum number of iterations
 *
 * @param[in] max_iter Maximum number of iterations.
 ***************************************************************************/
inline
void GIntegral::max_iter(const int& max_iter)
{
    m_max_iter = max_iter;
    return;
}


/***********************************************************************//**
 * @brief Return maximum number of iterations
 *
 * @return Maximum number of iterations.
 ***************************************************************************/
inline
const int& GIntegral::max_iter(void) const
{
    return m_max_iter;
}


/***********************************************************************//**
 * @brief Set precision
 *
 * @param[in] eps Precision.
 ***************************************************************************/
inline
void GIntegral::eps(const double& eps)
{
    m_eps = eps;
    return;
}


/***********************************************************************//**
 * @brief Get precision
 *
 * @return Precision.
 ***************************************************************************/
inline
const double& GIntegral::eps(void) const
{
    return m_eps;
}


/***********************************************************************//**
 * @brief Set silence flag
 *
 * @param[in] silent Silence flag.
 ***************************************************************************/
inline
void GIntegral::silent(const bool& silent)
{
    m_silent = silent;
    return;
}


/***********************************************************************//**
 * @brief Get silence flag
 *
 * @return True is class is silent, false otherwise.
 ***************************************************************************/
inline
const bool& GIntegral::silent(void) const
{
    return m_silent;
}


/***********************************************************************//**
 * @brief Set kernel
 *
 * @param[in] kernel Kernel.
 *
 * Sets the kernel for which the integral should be determined.
 ***************************************************************************/
inline
void GIntegral::kernel(GFunction* kernel)
{
    m_kernel = kernel;
    return;
}


/***********************************************************************//**
 * @brief Get kernel
 *
 * @return Kernel.
 ***************************************************************************/
inline
const GFunction* GIntegral::kernel(void) const
{
    return m_kernel;
}

#endif /* GINTEGRAL_HPP */