fit.h

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// Header file for the stimfit namespace
// Routines for fitting functions to data
// last revision: 08-08-2006
// C. Schmidt-Hieber, christsc@gmx.de
 
// 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 2
// 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, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

 
#ifndef _FITLIB_H
#define _FITLIB_H
 
#include "./stfnum.h"
#include <deque>
 
namespace stfnum {



template <typename T>
T linFit(
        const std::vector<T>& x,
        const std::vector<T>& y,
        T& m,
        T& c
);


double StfnumDll lmFit(const Vector_double& data, double dt,
                      const stfnum::storedFunc& fitFunc, const Vector_double& opts,
                      bool use_scaling, Vector_double& p, std::string& info, int& warning );


double flin(double x, const Vector_double& p);

void flin_init(const Vector_double& data, double base, double peak,
        double RTLoHi, double HalfWidth, double dt, Vector_double& pInit );


StfnumDll
stfnum::storedFunc initLinFunc();


 Vector_double get_scale(Vector_double& data, double oldx);


StfnumDll Vector_double LM_default_opts();
 
}
 
template <typename T>
T stfnum::linFit(const std::vector<T>& x,
        const std::vector<T>& y,
        T& m,
        T& c)
{
    double sum_x=0.0;
    double sum_y=0.0;
    double sum_xx=0.0;
    double sum_xy=0.0;
    for (unsigned n=0;n<x.size();++n) {
        sum_x+=x[n];
        sum_y+=y[n];
        sum_xx+=x[n]*x[n];
        sum_xy+=x[n]*y[n];
    }
    m=(T)(((T)x.size()*sum_xy-sum_x*sum_y)/((T)x.size()*sum_xx-sum_x*sum_x));
    c=(T)((sum_y-m*sum_x)/(T)x.size());
    T error = 0.0;
    for (unsigned n=0;n<x.size();++n) {
        error += (y[n]-(m*x[n]+c)) * (y[n]-(m*x[n]+c));
    }
    return error;

 
}
 
#endif