1*5ddc57e5SXin Li /*
2*5ddc57e5SXin Li * Library: lmfit (Levenberg-Marquardt least squares fitting)
3*5ddc57e5SXin Li *
4*5ddc57e5SXin Li * File: lmcurve.c
5*5ddc57e5SXin Li *
6*5ddc57e5SXin Li * Contents: Implements lmcurve_tyd(), a variant of lmcurve() that weighs
7*5ddc57e5SXin Li * data points y(t) with the inverse of the standard deviations dy.
8*5ddc57e5SXin Li *
9*5ddc57e5SXin Li * Copyright: Joachim Wuttke, Forschungszentrum Juelich GmbH (2004-2013)
10*5ddc57e5SXin Li *
11*5ddc57e5SXin Li * License: see ../COPYING (FreeBSD)
12*5ddc57e5SXin Li *
13*5ddc57e5SXin Li * Homepage: apps.jcns.fz-juelich.de/lmfit
14*5ddc57e5SXin Li */
15*5ddc57e5SXin Li
16*5ddc57e5SXin Li #include "lmmin.h"
17*5ddc57e5SXin Li
18*5ddc57e5SXin Li typedef struct {
19*5ddc57e5SXin Li const double* t;
20*5ddc57e5SXin Li const double* y;
21*5ddc57e5SXin Li const double* dy;
22*5ddc57e5SXin Li double (*f)(const double t, const double* par);
23*5ddc57e5SXin Li } lmcurve_tyd_data_struct;
24*5ddc57e5SXin Li
lmcurve_tyd_evaluate(const double * par,const int m_dat,const void * data,double * fvec,int * info)25*5ddc57e5SXin Li void lmcurve_tyd_evaluate(
26*5ddc57e5SXin Li const double* par, const int m_dat, const void* data, double* fvec,
27*5ddc57e5SXin Li int* info)
28*5ddc57e5SXin Li {
29*5ddc57e5SXin Li lmcurve_tyd_data_struct* D = (lmcurve_tyd_data_struct*)data;
30*5ddc57e5SXin Li int i;
31*5ddc57e5SXin Li for (i = 0; i < m_dat; i++)
32*5ddc57e5SXin Li fvec[i] = ( D->y[i] - D->f(D->t[i], par) ) / D->dy[i];
33*5ddc57e5SXin Li }
34*5ddc57e5SXin Li
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*5ddc57e5SXin Li void lmcurve_tyd(
36*5ddc57e5SXin Li const int n_par, double* par, const int m_dat,
37*5ddc57e5SXin Li const double* t, const double* y, const double* dy,
38*5ddc57e5SXin Li double (*f)(const double t, const double* par),
39*5ddc57e5SXin Li const lm_control_struct* control, lm_status_struct* status)
40*5ddc57e5SXin Li {
41*5ddc57e5SXin Li lmcurve_tyd_data_struct data = { t, y, dy, f };
42*5ddc57e5SXin Li
43*5ddc57e5SXin Li lmmin(n_par, par, m_dat, (const void*)&data, lmcurve_tyd_evaluate,
44*5ddc57e5SXin Li control, status);
45*5ddc57e5SXin Li }
46