1 /*
2  * Library:   lmfit (Levenberg-Marquardt least squares fitting)
3  *
4  * File:      lmstruct.h
5  *
6  * Contents:  Declarations of parameter records, used in lmmin.h and lmcurve.h
7  *
8  * Copyright: Joachim Wuttke, Forschungszentrum Juelich GmbH (2004-2013)
9  *
10  * License:   see ../COPYING (FreeBSD)
11  *
12  * Homepage:  apps.jcns.fz-juelich.de/lmfit
13  */
14 
15 #ifndef LMSTRUCT_H
16 #define LMSTRUCT_H
17 
18 #ifdef __cplusplus
19 extern "C" {
20 #endif
21 
22 #include <stdio.h>
23 
24 /* Collection of input parameters for fit control. */
25 typedef struct {
26     double ftol;      /* Relative error desired in the sum of squares.
27                          Termination occurs when both the actual and
28                          predicted relative reductions in the sum of squares
29                          are at most ftol. */
30     double xtol;      /* Relative error between last two approximations.
31                          Termination occurs when the relative error between
32                          two consecutive iterates is at most xtol. */
33     double gtol;      /* Orthogonality desired between fvec and its derivs.
34                          Termination occurs when the cosine of the angle
35                          between fvec and any column of the Jacobian is at
36                          most gtol in absolute value. */
37     double epsilon;   /* Step used to calculate the Jacobian, should be
38                          slightly larger than the relative error in the
39                          user-supplied functions. */
40     double stepbound; /* Used in determining the initial step bound. This
41                          bound is set to the product of stepbound and the
42                          Euclidean norm of diag*x if nonzero, or else to
43                          stepbound itself. In most cases stepbound should lie
44                          in the interval (0.1,100.0). Generally, the value
45                          100.0 is recommended. */
46     int patience;     /* Used to set the maximum number of function evaluations
47                          to patience*(number_of_parameters+1). */
48     int scale_diag;   /* If 1, the variables will be rescaled internally.
49                          Recommended value is 1. */
50     FILE** stream;    /* Pointer to output stream to write to. */
51     int verbosity;    /* OR'ed: 1: print some messages; 2: print Jacobian. */
52     int n_maxpri;     /* -1, or max number of parameters to print. */
53     int m_maxpri;     /* -1, or max number of residuals to print. */
54 } lm_control_struct;
55 
56 /* Collection of output parameters for status info. */
57 typedef struct {
58     double fnorm;     /* norm of the residue vector fvec. */
59     int nfev;         /* actual number of iterations. */
60     int outcome;      /* Status indicator. Nonnegative values are used as index
61                          for the message text lm_infmsg, set in lmmin.c. */
62     int userbreak;    /* Set when function evaluation requests termination. */
63 } lm_status_struct;
64 
65 /* Preset (and recommended) control parameter settings. */
66 extern const lm_control_struct lm_control_double;
67 extern const lm_control_struct lm_control_float;
68 
69 /* Preset message texts. */
70 
71 extern const char *lm_infmsg[];
72 extern const char *lm_shortmsg[];
73 
74 #ifdef __cplusplus
75 }
76 #endif
77 
78 #endif /* LMSTRUCT_H */
79