1 /*
2 * Library: lmfit (Levenberg-Marquardt least squares fitting)
3 *
4 * File: lmcurve.c
5 *
6 * Contents: Implements lmcurve_tyd(), a variant of lmcurve() that weighs
7 * data points y(t) with the inverse of the standard deviations dy.
8 *
9 * Copyright: Joachim Wuttke, Forschungszentrum Juelich GmbH (2004-2013)
10 *
11 * License: see ../COPYING (FreeBSD)
12 *
13 * Homepage: apps.jcns.fz-juelich.de/lmfit
14 */
15
16 #include "lmmin.h"
17
18 typedef struct {
19 const double* t;
20 const double* y;
21 const double* dy;
22 double (*f)(const double t, const double* par);
23 } lmcurve_tyd_data_struct;
24
lmcurve_tyd_evaluate(const double * par,const int m_dat,const void * data,double * fvec,int * info)25 void lmcurve_tyd_evaluate(
26 const double* par, const int m_dat, const void* data, double* fvec,
27 int* info)
28 {
29 lmcurve_tyd_data_struct* D = (lmcurve_tyd_data_struct*)data;
30 int i;
31 for (i = 0; i < m_dat; i++)
32 fvec[i] = ( D->y[i] - D->f(D->t[i], par) ) / D->dy[i];
33 }
34
lmcurve_tyd(const int n_par,double * par,const int m_dat,const double * t,const double * y,const double * dy,double (* f)(const double t,const double * par),const lm_control_struct * control,lm_status_struct * status)35 void lmcurve_tyd(
36 const int n_par, double* par, const int m_dat,
37 const double* t, const double* y, const double* dy,
38 double (*f)(const double t, const double* par),
39 const lm_control_struct* control, lm_status_struct* status)
40 {
41 lmcurve_tyd_data_struct data = { t, y, dy, f };
42
43 lmmin(n_par, par, m_dat, (const void*)&data, lmcurve_tyd_evaluate,
44 control, status);
45 }
46