PeakFunctionIntegrator.h

#ifndef PEAKFUNCTIONINTEGRATOR_H
#define PEAKFUNCTIONINTEGRATOR_H

#include "MantidSINQ/DllConfig.h"
#include "MantidAPI/IPeakFunction.h"
#include "gsl/gsl_integration.h"

namespace Mantid {
namespace Poldi {

/** PeakFunctionIntegrator :
 *
  General integration of peaks (in the form of IPeakFunction) by wrapping the
  corresponding GSL-functions. Integration with infinity limits is supported.

    @author Michael Wedel, Paul Scherrer Institut - SINQ
    @date 24/04/2014

    Copyright © 2014 PSI-MSS

  This file is part of Mantid.

  Mantid 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.

  Mantid 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 change history is stored at: <https://github.com/mantidproject/mantid>
  Code Documentation is available at: <http://doxygen.mantidproject.org>
*/

using namespace Mantid::API;

struct MANTID_SINQ_DLL IntegrationResult {
    double result;
    double error;
    size_t intervals;

    int errorCode;
    bool success;
};

class MANTID_SINQ_DLL PeakFunctionIntegrator {
public:
    PeakFunctionIntegrator(double requiredRelativePrecision = 1e-8);
    virtual ~PeakFunctionIntegrator();

    void setRequiredRelativePrecision(double newPrecision);
    double requiredRelativePrecision() const;

    IntegrationResult integrateInfinity(IPeakFunction_const_sptr peakFunction) const;
    IntegrationResult integratePositiveInfinity(IPeakFunction_const_sptr peakFunction, double lowerLimit) const;
    IntegrationResult integrateNegativeInfinity(IPeakFunction_const_sptr peakFunction, double upperLimit) const;

    IntegrationResult integrate(IPeakFunction_const_sptr peakFunction, double lowerLimit, double upperLimit) const;

protected:
    gsl_function getGSLFunction(IPeakFunction_const_sptr peakFunction) const;
    void throwIfInvalid(IPeakFunction_const_sptr peakFunction) const;

    gsl_integration_workspace *m_integrationWorkspace;

    double m_relativePrecision;
};

double gsl_peak_wrapper(double x, void *parameters);

}
}

#endif // PEAKFUNCTIONINTEGRATOR_H