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fit.c
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fit.c
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#ifndef lint
static char *RCSid = "$Id: fit.c,v 1.19 1998/12/02 18:37:50 lhecking Exp $";
#endif
/*
* Nonlinear least squares fit according to the
* Marquardt-Levenberg-algorithm
*
* added as Patch to Gnuplot (v3.2 and higher)
* by Carsten Grammes
* Experimental Physics, University of Saarbruecken, Germany
*
* Internet address: cagr@rz.uni-sb.de
*
* Copyright of this module: 1993, 1998 Carsten Grammes
*
* Permission to use, copy, and distribute this software and its
* documentation for any purpose with or without fee is hereby granted,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation.
*
* This software is provided "as is" without express or implied warranty.
*
* 930726: Recoding of the Unix-like raw console I/O routines by:
* Michele Marziani (marziani@ferrara.infn.it)
* drd: start unitialised variables at 1 rather than NEARLY_ZERO
* (fit is more likely to converge if started from 1 than 1e-30 ?)
*
* HBB (Broeker@physik.rwth-aachen.de) : fit didn't calculate the errors
* in the 'physically correct' (:-) way, if a third data column containing
* the errors (or 'uncertainties') of the input data was given. I think
* I've fixed that, but I'm not sure I really understood the M-L-algo well
* enough to get it right. I deduced my change from the final steps of the
* equivalent algorithm for the linear case, which is much easier to
* understand. (I also made some minor, mostly cosmetic changes)
*
* HBB (again): added error checking for negative covar[i][i] values and
* for too many parameters being specified.
*
* drd: allow 3d fitting. Data value is now called fit_z internally,
* ie a 2d fit is z vs x, and a 3d fit is z vs x and y.
*
* Lars Hecking : review update command, for VMS in particular, where
* it is not necessary to rename the old file.
*
* HBB, 971023: lifted fixed limit on number of datapoints, and number
* of parameters.
*/
#define FIT_MAIN
#include <signal.h>
#include "plot.h"
#include "matrix.h"
#include "fit.h"
#include "setshow.h" /* for load_range */
#include "alloc.h"
#if defined(MSDOS) || defined(DOS386) /* non-blocking IO stuff */
# include <io.h>
# ifndef _Windows /* WIN16 does define MSDOS .... */
# include <conio.h>
# endif
# include <dos.h>
#else /* !(MSDOS || DOS386) */
# ifndef VMS
# include <fcntl.h>
# endif /* !VMS */
#endif /* !(MSDOS || DOS386) */
#if defined(ATARI) || defined(MTOS)
# define getchx() Crawcin()
static int kbhit(void);
#endif
#define STANDARD stderr /* compatible with gnuplot philosophy */
#define BACKUP_SUFFIX ".old"
/* access external global variables (ought to make a globals.h someday) */
extern struct udft_entry *dummy_func;
extern char dummy_var[MAX_NUM_VAR][MAX_ID_LEN+1];
extern char c_dummy_var[MAX_NUM_VAR][MAX_ID_LEN+1];
extern int c_token;
extern int df_datum, df_line_number;
enum marq_res {
OK, ERROR, BETTER, WORSE
};
typedef enum marq_res marq_res_t;
#ifdef INFINITY
# undef INFINITY
#endif
#define INFINITY 1e30
#define NEARLY_ZERO 1e-30
/* create new variables with this value (was NEARLY_ZERO) */
#define INITIAL_VALUE 1.0
/* Relative change for derivatives */
#define DELTA 0.001
#define MAX_DATA 2048
#define MAX_PARAMS 32
#define MAX_LAMBDA 1e20
#define MIN_LAMBDA 1e-20
#define LAMBDA_UP_FACTOR 10
#define LAMBDA_DOWN_FACTOR 10
#if defined(MSDOS) || defined(OS2) || defined(DOS386)
# define PLUSMINUS "\xF1" /* plusminus sign */
#else
# define PLUSMINUS "+/-"
#endif
#define LASTFITCMDLENGTH 511
/* HBB 971023: new, allow for dynamic adjustment of these: */
static int max_data;
static int max_params;
static double epsilon = 1e-5; /* convergence limit */
static int maxiter = 0; /* HBB 970304: maxiter patch */
static char fit_script[128];
static char logfile[128] = "fit.log";
static char *FIXED = "# FIXED";
static char *GNUFITLOG = "FIT_LOG";
static char *FITLIMIT = "FIT_LIMIT";
static char *FITSTARTLAMBDA = "FIT_START_LAMBDA";
static char *FITLAMBDAFACTOR = "FIT_LAMBDA_FACTOR";
static char *FITMAXITER = "FIT_MAXITER"; /* HBB 970304: maxiter patch */
static char *FITSCRIPT = "FIT_SCRIPT";
static char *DEFAULT_CMD = "replot"; /* if no fitscript spec. */
static char last_fit_command[LASTFITCMDLENGTH+1] = "";
static FILE *log_f = NULL;
static int num_data, num_params;
static int columns;
static double *fit_x = 0, *fit_y = 0, *fit_z = 0, *err_data = 0, *a = 0;
static TBOOLEAN ctrlc_flag = FALSE;
static TBOOLEAN user_stop = FALSE;
static struct udft_entry func;
typedef char fixstr[MAX_ID_LEN+1];
static fixstr *par_name;
static double startup_lambda = 0, lambda_down_factor = LAMBDA_DOWN_FACTOR,
lambda_up_factor = LAMBDA_UP_FACTOR;
/*****************************************************************
internal Prototypes
*****************************************************************/
static RETSIGTYPE ctrlc_handle __PROTO((int an_int));
static void ctrlc_setup __PROTO((void));
static void printmatrix __PROTO((double **C, int m, int n));
static void print_matrix_and_vectors __PROTO((double **C, double *d, double *r, int m, int n));
static marq_res_t marquardt __PROTO((double a[], double **alpha, double *chisq,
double *lambda));
static TBOOLEAN analyze __PROTO((double a[], double **alpha, double beta[],
double *chisq));
static void calculate __PROTO((double *zfunc, double **dzda, double a[]));
static void call_gnuplot __PROTO((double *par, double *data));
static TBOOLEAN fit_interrupt __PROTO((void));
static TBOOLEAN regress __PROTO((double a[]));
static void show_fit __PROTO((int i, double chisq, double last_chisq, double *a,
double lambda, FILE * device));
static TBOOLEAN is_empty __PROTO((char *s));
static TBOOLEAN is_variable __PROTO((char *s));
static double getdvar __PROTO((char *varname));
static double createdvar __PROTO((char *varname, double value));
static void splitpath __PROTO((char *s, char *p, char *f));
static void backup_file __PROTO((char *, const char *));
/*****************************************************************
Small function to write the last fit command into a file
Arg: Pointer to the file; if NULL, nothing is written,
but only the size of the string is returned.
*****************************************************************/
int wri_to_fil_last_fit_cmd(fp)
FILE *fp;
{
if (fp == NULL)
return strlen(last_fit_command);
else
return fprintf(fp, "%s", last_fit_command);
}
/*****************************************************************
This is called when a SIGINT occurs during fit
*****************************************************************/
static RETSIGTYPE ctrlc_handle(an_int)
int an_int;
{
#ifdef OS2
(void) signal(an_int, SIG_ACK);
#else
/* reinstall signal handler (necessary on SysV) */
(void) signal(SIGINT, (sigfunc) ctrlc_handle);
#endif
ctrlc_flag = TRUE;
}
/*****************************************************************
setup the ctrl_c signal handler
*****************************************************************/
static void ctrlc_setup()
{
/*
* MSDOS defines signal(SIGINT) but doesn't handle it through
* real interrupts. So there remain cases in which a ctrl-c may
* be uncaught by signal. We must use kbhit() instead that really
* serves the keyboard interrupt (or write an own interrupt func
* which also generates #ifdefs)
*
* I hope that other OSes do it better, if not... add #ifdefs :-(
*/
#if (defined(__EMX__) || !defined(MSDOS) && !defined(DOS386)) && !defined(ATARI) && !defined(MTOS)
(void) signal(SIGINT, (sigfunc) ctrlc_handle);
#endif
}
/*****************************************************************
getch that handles also function keys etc.
*****************************************************************/
#if defined(MSDOS) || defined(DOS386)
/* HBB 980317: added a prototype... */
int getchx __PROTO((void));
int getchx()
{
register int c = getch();
if (!c || c == 0xE0) {
c <<= 8;
c |= getch();
}
return c;
}
#endif
/*****************************************************************
in case of fatal errors
*****************************************************************/
void error_ex()
{
char *sp;
strncpy(fitbuf, " ", 9); /* start after GNUPLOT> */
sp = strchr(fitbuf, NUL);
while (*--sp == '\n')
;
strcpy(sp + 1, "\n\n"); /* terminate with exactly 2 newlines */
fprintf(STANDARD, fitbuf);
if (log_f) {
fprintf(log_f, "BREAK: %s", fitbuf);
(void) fclose(log_f);
log_f = NULL;
}
if (func.at) {
free(func.at); /* release perm. action table */
func.at = (struct at_type *) NULL;
}
/* restore original SIGINT function */
#if !defined(ATARI) && !defined(MTOS)
interrupt_setup();
#endif
bail_to_command_line();
}
/*****************************************************************
New utility routine: print a matrix (for debugging the alg.)
*****************************************************************/
static void printmatrix(C, m, n)
double **C;
int m, n;
{
int i, j;
for (i = 0; i < m; i++) {
for (j = 0; j < n - 1; j++)
Dblf2("%.8g |", C[i][j]);
Dblf2("%.8g\n", C[i][j]);
}
Dblf("\n");
}
/**************************************************************************
Yet another debugging aid: print matrix, with diff. and residue vector
**************************************************************************/
static void print_matrix_and_vectors(C, d, r, m, n)
double **C;
double *d, *r;
int m, n;
{
int i, j;
for (i = 0; i < m; i++) {
for (j = 0; j < n; j++)
Dblf2("%8g ", C[i][j]);
Dblf3("| %8g | %8g\n", d[i], r[i]);
}
Dblf("\n");
}
/*****************************************************************
Marquardt's nonlinear least squares fit
*****************************************************************/
static marq_res_t marquardt(a, C, chisq, lambda)
double a[];
double **C;
double *chisq;
double *lambda;
{
int i, j;
static double *da = 0, /* delta-step of the parameter */
*temp_a = 0, /* temptative new params set */
*d = 0, *tmp_d = 0, **tmp_C = 0, *residues = 0;
double tmp_chisq;
/* Initialization when lambda == -1 */
if (*lambda == -1) { /* Get first chi-square check */
TBOOLEAN analyze_ret;
temp_a = vec(num_params);
d = vec(num_data + num_params);
tmp_d = vec(num_data + num_params);
da = vec(num_params);
residues = vec(num_data + num_params);
tmp_C = matr(num_data + num_params, num_params);
analyze_ret = analyze(a, C, d, chisq);
/* Calculate a useful startup value for lambda, as given by Schwarz */
/* FIXME: this is doesn't turn out to be much better, really... */
if (startup_lambda != 0)
*lambda = startup_lambda;
else {
*lambda = 0;
for (i = 0; i < num_data; i++)
for (j = 0; j < num_params; j++)
*lambda += C[i][j] * C[i][j];
*lambda = sqrt(*lambda / num_data / num_params);
}
/* Fill in the lower square part of C (the diagonal is filled in on
each iteration, see below) */
for (i = 0; i < num_params; i++)
for (j = 0; j < i; j++)
C[num_data + i][j] = 0, C[num_data + j][i] = 0;
/*printmatrix(C, num_data+num_params, num_params); */
return analyze_ret ? OK : ERROR;
}
/* once converged, free dynamic allocated vars */
if (*lambda == -2) {
free(d);
free(tmp_d);
free(da);
free(temp_a);
free(residues);
free_matr(tmp_C);
return OK;
}
/* Givens calculates in-place, so make working copies of C and d */
for (j = 0; j < num_data + num_params; j++)
memcpy(tmp_C[j], C[j], num_params * sizeof(double));
memcpy(tmp_d, d, num_data * sizeof(double));
/* fill in additional parts of tmp_C, tmp_d */
for (i = 0; i < num_params; i++) {
/* fill in low diag. of tmp_C ... */
tmp_C[num_data + i][i] = *lambda;
/* ... and low part of tmp_d */
tmp_d[num_data + i] = 0;
}
/* printmatrix(tmp_C, num_data+num_params, num_params); */
/* FIXME: residues[] isn't used at all. Why? Should it be used? */
Givens(tmp_C, tmp_d, da, residues, num_params + num_data, num_params, 1);
/*print_matrix_and_vectors (tmp_C, tmp_d, residues,
num_params+num_data, num_params); */
/* check if trial did ameliorate sum of squares */
for (j = 0; j < num_params; j++)
temp_a[j] = a[j] + da[j];
if (!analyze(temp_a, tmp_C, tmp_d, &tmp_chisq)) {
/* FIXME: will never be reached: always returns TRUE */
return ERROR;
}
if (tmp_chisq < *chisq) { /* Success, accept new solution */
if (*lambda > MIN_LAMBDA) {
(void) putc('/', stderr);
*lambda /= lambda_down_factor;
}
*chisq = tmp_chisq;
for (j = 0; j < num_data; j++) {
memcpy(C[j], tmp_C[j], num_params * sizeof(double));
d[j] = tmp_d[j];
}
for (j = 0; j < num_params; j++)
a[j] = temp_a[j];
return BETTER;
} else { /* failure, increase lambda and return */
(void) putc('*', stderr);
*lambda *= lambda_up_factor;
return WORSE;
}
}
/* FIXME: in the new code, this function doesn't really do enough to be
* useful. Maybe it ought to be deleted, i.e. integrated with
* calculate() ?
*/
/*****************************************************************
compute chi-square and numeric derivations
*****************************************************************/
static TBOOLEAN analyze(a, C, d, chisq)
double a[];
double **C;
double d[];
double *chisq;
{
/*
* used by marquardt to evaluate the linearized fitting matrix C
* and vector d, fills in only the top part of C and d
* I don't use a temporary array zfunc[] any more. Just use
* d[] instead.
*/
int i, j;
*chisq = 0;
calculate(d, C, a);
for (i = 0; i < num_data; i++) {
/* note: order reversed, as used by Schwarz */
d[i] = (d[i] - fit_z[i]) / err_data[i];
*chisq += d[i] * d[i];
for (j = 0; j < num_params; j++)
C[i][j] /= err_data[i];
}
/* FIXME: why return a value that is always TRUE ? */
return TRUE;
}
/* To use the more exact, but slower two-side formula, activate the
following line: */
/*#define TWO_SIDE_DIFFERENTIATION */
/*****************************************************************
compute function values and partial derivatives of chi-square
*****************************************************************/
static void calculate(zfunc, dzda, a)
double *zfunc;
double **dzda;
double a[];
{
int k, p;
double tmp_a;
double *tmp_high, *tmp_pars;
#ifdef TWO_SIDE_DIFFERENTIATION
double *tmp_low;
#endif
tmp_high = vec(num_data); /* numeric derivations */
#ifdef TWO_SIDE_DIFFERENTIATION
tmp_low = vec(num_data);
#endif
tmp_pars = vec(num_params);
/* first function values */
call_gnuplot(a, zfunc);
/* then derivatives */
for (p = 0; p < num_params; p++)
tmp_pars[p] = a[p];
for (p = 0; p < num_params; p++) {
tmp_a = fabs(a[p]) < NEARLY_ZERO ? NEARLY_ZERO : a[p];
tmp_pars[p] = tmp_a * (1 + DELTA);
call_gnuplot(tmp_pars, tmp_high);
#ifdef TWO_SIDE_DIFFERENTIATION
tmp_pars[p] = tmp_a * (1 - DELTA);
call_gnuplot(tmp_pars, tmp_low);
#endif
for (k = 0; k < num_data; k++)
#ifdef TWO_SIDE_DIFFERENTIATION
dzda[k][p] = (tmp_high[k] - tmp_low[k]) / (2 * tmp_a * DELTA);
#else
dzda[k][p] = (tmp_high[k] - zfunc[k]) / (tmp_a * DELTA);
#endif
tmp_pars[p] = a[p];
}
#ifdef TWO_SIDE_DIFFERENTIATION
free(tmp_low);
#endif
free(tmp_high);
free(tmp_pars);
}
/*****************************************************************
call internal gnuplot functions
*****************************************************************/
static void call_gnuplot(par, data)
double *par;
double *data;
{
int i;
struct value v;
/* set parameters first */
for (i = 0; i < num_params; i++) {
(void) Gcomplex(&v, par[i], 0.0);
setvar(par_name[i], v);
}
for (i = 0; i < num_data; i++) {
/* calculate fit-function value */
(void) Gcomplex(&func.dummy_values[0], fit_x[i], 0.0);
(void) Gcomplex(&func.dummy_values[1], fit_y[i], 0.0);
evaluate_at(func.at, &v);
if (undefined)
Eex("Undefined value during function evaluation");
data[i] = real(&v);
}
}
/*****************************************************************
handle user interrupts during fit
*****************************************************************/
static TBOOLEAN fit_interrupt()
{
while (TRUE) {
fprintf(STANDARD, "\n\n(S)top fit, (C)ontinue, (E)xecute FIT_SCRIPT: ");
switch (getc(stdin)) {
case EOF:
case 's':
case 'S':
fprintf(STANDARD, "Stop.");
user_stop = TRUE;
return FALSE;
case 'c':
case 'C':
fprintf(STANDARD, "Continue.");
return TRUE;
case 'e':
case 'E':{
int i;
struct value v;
char *tmp;
tmp = (fit_script != 0 && *fit_script) ? fit_script : DEFAULT_CMD;
fprintf(STANDARD, "executing: %s", tmp);
/* set parameters visible to gnuplot */
for (i = 0; i < num_params; i++) {
(void) Gcomplex(&v, a[i], 0.0);
setvar(par_name[i], v);
}
sprintf(input_line, tmp);
(void) do_line();
}
}
}
return TRUE;
}
/*****************************************************************
frame routine for the marquardt-fit
*****************************************************************/
static TBOOLEAN regress(a)
double a[];
{
double **covar, *dpar, **C, chisq, last_chisq, lambda;
int iter, i, j;
marq_res_t res;
chisq = last_chisq = INFINITY;
C = matr(num_data + num_params, num_params);
lambda = -1; /* use sign as flag */
iter = 0; /* iteration counter */
/* ctrlc now serves as Hotkey */
ctrlc_setup();
/* Initialize internal variables and 1st chi-square check */
if ((res = marquardt(a, C, &chisq, &lambda)) == ERROR)
Eex("FIT: error occured during fit");
res = BETTER;
Dblf("\nInitial set of free parameters:\n");
show_fit(iter, chisq, chisq, a, lambda, STANDARD);
show_fit(iter, chisq, chisq, a, lambda, log_f);
/* MAIN FIT LOOP: do the regression iteration */
/* HBB 981118: initialize new variable 'user_break' */
user_stop = FALSE;
do {
/*
* MSDOS defines signal(SIGINT) but doesn't handle it through
* real interrupts. So there remain cases in which a ctrl-c may
* be uncaught by signal. We must use kbhit() instead that really
* serves the keyboard interrupt (or write an own interrupt func
* which also generates #ifdefs)
*
* I hope that other OSes do it better, if not... add #ifdefs :-(
* EMX does not have kbhit.
*
* HBB: I think this can be enabled for DJGPP V2. SIGINT is actually
* handled there, AFAIK.
*/
#if ((defined(MSDOS) || defined(DOS386)) && !defined(__EMX__)) || defined(ATARI) || defined(MTOS)
if (kbhit()) {
do {
getchx();
} while (kbhit());
ctrlc_flag = TRUE;
}
#endif
if (ctrlc_flag) {
show_fit(iter, chisq, last_chisq, a, lambda, STANDARD);
ctrlc_flag = FALSE;
if (!fit_interrupt()) /* handle keys */
break;
}
if (res == BETTER) {
iter++;
last_chisq = chisq;
}
if ((res = marquardt(a, C, &chisq, &lambda)) == BETTER)
show_fit(iter, chisq, last_chisq, a, lambda, STANDARD);
} while ((res != ERROR)
&& (lambda < MAX_LAMBDA)
&& ((maxiter == 0) || (iter <= maxiter))
&& (res == WORSE
|| ((chisq > NEARLY_ZERO)
? ((last_chisq - chisq) / chisq)
: (last_chisq - chisq)) > epsilon
)
);
/* fit done */
#if !defined(ATARI) && !defined(MTOS)
/* restore original SIGINT function */
interrupt_setup();
#endif
/* HBB 970304: the maxiter patch: */
if ((maxiter > 0) && (iter > maxiter)) {
Dblf2("\nMaximum iteration count (%d) reached. Fit stopped.\n", maxiter);
} else if (user_stop) {
Dblf2("\nThe fit was stopped by the user after %d iterations.\n", iter);
} else {
Dblf2("\nAfter %d iterations the fit converged.\n", iter);
}
Dblf2("final sum of squares of residuals : %g\n", chisq);
if (chisq > NEARLY_ZERO) {
Dblf2("rel. change during last iteration : %g\n\n", (chisq - last_chisq) / chisq);
} else {
Dblf2("abs. change during last iteration : %g\n\n", (chisq - last_chisq));
}
if (res == ERROR)
Eex("FIT: error occured during fit");
/* compute errors in the parameters */
if (num_data == num_params) {
int i;
Dblf("\nExactly as many data points as there are parameters.\n");
Dblf("In this degenerate case, all errors are zero by definition.\n\n");
Dblf("Final set of parameters \n");
Dblf("======================= \n\n");
for (i = 0; i < num_params; i++)
Dblf3("%-15.15s = %-15g\n", par_name[i], a[i]);
} else if (chisq < NEARLY_ZERO) {
int i;
Dblf("\nHmmmm.... Sum of squared residuals is zero. Can't compute errors.\n\n");
Dblf("Final set of parameters \n");
Dblf("======================= \n\n");
for (i = 0; i < num_params; i++)
Dblf3("%-15.15s = %-15g\n", par_name[i], a[i]);
} else {
/* HBB 981117: change from L.Hart. I'm not yet fully convinced of this one */
if (columns < 3) {
Dblf2("unit weights: stdfit = sqrt(WSSR/ndf) = %g\n\n", sqrt(chisq / (num_data - num_params)));
} else {
Dblf2("weighted fit: reduced chisquare = WSSR/ndf = %g\n\n", chisq / (num_data - num_params));
}
/* get covariance-, Korrelations- and Kurvature-Matrix */
/* and errors in the parameters */
/* compute covar[][] directly from C */
Givens(C, 0, 0, 0, num_data, num_params, 0);
/*printmatrix(C, num_params, num_params); */
/* Use lower square of C for covar */
covar = C + num_data;
Invert_RtR(C, covar, num_params);
/*printmatrix(covar, num_params, num_params); */
/* calculate unscaled parameter errors in dpar[]: */
dpar = vec(num_params);
for (i = 0; i < num_params; i++) {
/* FIXME: can this still happen ? */
if (covar[i][i] <= 0.0) /* HBB: prevent floating point exception later on */
Eex("Calculation error: non-positive diagonal element in covar. matrix");
dpar[i] = sqrt(covar[i][i]);
}
/* transform covariances into correlations */
for (i = 0; i < num_params; i++) {
/* only lower triangle needs to be handled */
for (j = 0; j <= i; j++)
covar[i][j] /= dpar[i] * dpar[j];
}
/* scale parameter errors based on chisq */
chisq = sqrt(chisq / (num_data - num_params));
for (i = 0; i < num_params; i++)
dpar[i] *= chisq;
Dblf("Final set of parameters Asymptotic Standard Error\n");
Dblf("======================= ==========================\n\n");
for (i = 0; i < num_params; i++) {
double temp =
(fabs(a[i]) < NEARLY_ZERO) ? 0.0 : fabs(100.0 * dpar[i] / a[i]);
Dblf6("%-15.15s = %-15g %-3.3s %-12.4g (%.4g%%)\n",
par_name[i], a[i], PLUSMINUS, dpar[i], temp);
}
Dblf("\n\ncorrelation matrix of the fit parameters:\n\n");
Dblf(" ");
for (j = 0; j < num_params; j++)
Dblf2("%-6.6s ", par_name[j]);
Dblf("\n");
for (i = 0; i < num_params; i++) {
Dblf2("%-15.15s", par_name[i]);
for (j = 0; j <= i; j++) {
/* Only print lower triangle of symmetric matrix */
Dblf2("%6.3f ", covar[i][j]);
}
Dblf("\n");
}
free(dpar);
}
/* call destructor for allocated vars */
lambda = -2; /* flag value, meaning 'destruct!' */
(void) marquardt(a, C, &chisq, &lambda);
free_matr(C);
return TRUE;
}
/*****************************************************************
display actual state of the fit
*****************************************************************/
static void show_fit(i, chisq, last_chisq, a, lambda, device)
int i;
double chisq;
double last_chisq;
double *a;
double lambda;
FILE *device;
{
int k;
fprintf(device, "\n\n\
Iteration %d\n\
WSSR : %-15g delta(WSSR)/WSSR : %g\n\
delta(WSSR) : %-15g limit for stopping : %g\n\
lambda : %g\n\n%s parameter values\n\n",
i, chisq, chisq > NEARLY_ZERO ? (chisq - last_chisq) / chisq : 0.0,
chisq - last_chisq, epsilon, lambda,
(i > 0 ? "resultant" : "initial"));
for (k = 0; k < num_params; k++)
fprintf(device, "%-15.15s = %g\n", par_name[k], a[k]);
}
/*****************************************************************
is_empty: check for valid string entries
*****************************************************************/
static TBOOLEAN is_empty(s)
char *s;
{
while (*s == ' ' || *s == '\t' || *s == '\n')
s++;
return (TBOOLEAN) (*s == '#' || *s == '\0');
}
/*****************************************************************
get next word of a multi-word string, advance pointer
*****************************************************************/
char *get_next_word(s, subst)
char **s;
char *subst;
{
char *tmp = *s;
while (*tmp == ' ' || *tmp == '\t' || *tmp == '=')
tmp++;
if (*tmp == '\n' || *tmp == '\0') /* not found */
return NULL;
if ((*s = strpbrk(tmp, " =\t\n")) == NULL)
*s = tmp + strlen(tmp);
*subst = **s;
*(*s)++ = '\0';
return tmp;
}
/*****************************************************************
check for variable identifiers
*****************************************************************/
static TBOOLEAN is_variable(s)
char *s;
{
while (*s != '\0') {
if (!isalnum((int) *s) && *s != '_')
return FALSE;
s++;
}
return TRUE;
}
/*****************************************************************
first time settings
*****************************************************************/
void init_fit()
{
func.at = (struct at_type *) NULL; /* need to parse 1 time */
}
/*****************************************************************
Set a GNUPLOT user-defined variable
******************************************************************/
void setvar(varname, data)
char *varname;
struct value data;
{
register struct udvt_entry *udv_ptr = first_udv, *last = first_udv;
/* check if it's already in the table... */
while (udv_ptr) {
last = udv_ptr;
if (!strcmp(varname, udv_ptr->udv_name))
break;
udv_ptr = udv_ptr->next_udv;
}
if (!udv_ptr) { /* generate new entry */
last->next_udv = udv_ptr = (struct udvt_entry *)
gp_alloc((unsigned int) sizeof(struct udvt_entry), "fit setvar");
udv_ptr->next_udv = NULL;
}
safe_strncpy(udv_ptr->udv_name, varname, sizeof(udv_ptr->udv_name));
udv_ptr->udv_value = data;
udv_ptr->udv_undef = FALSE;
}
/*****************************************************************
Read INTGR Variable value, return 0 if undefined or wrong type
*****************************************************************/
int getivar(varname)
char *varname;
{
register struct udvt_entry *udv_ptr = first_udv;
while (udv_ptr) {
if (!strcmp(varname, udv_ptr->udv_name))
return udv_ptr->udv_value.type == INTGR
? udv_ptr->udv_value.v.int_val /* valid */
: 0; /* wrong type */
udv_ptr = udv_ptr->next_udv;
}
return 0; /* not in table */
}
/*****************************************************************
Read DOUBLE Variable value, return 0 if undefined or wrong type
I dont think it's a problem that it's an integer - div
*****************************************************************/
static double getdvar(varname)
char *varname;
{
register struct udvt_entry *udv_ptr = first_udv;
for (; udv_ptr; udv_ptr = udv_ptr->next_udv)
if (strcmp(varname, udv_ptr->udv_name) == 0)
return real(&(udv_ptr->udv_value));
/* get here => not found */
return 0;
}
/*****************************************************************
like getdvar, but
- convert it from integer to real if necessary
- create it with value INITIAL_VALUE if not found or undefined
*****************************************************************/
static double createdvar(varname, value)
char *varname;
double value;
{
register struct udvt_entry *udv_ptr = first_udv;
for (; udv_ptr; udv_ptr = udv_ptr->next_udv)
if (strcmp(varname, udv_ptr->udv_name) == 0) {
if (udv_ptr->udv_undef) {
udv_ptr->udv_undef = 0;
(void) Gcomplex(&udv_ptr->udv_value, value, 0.0);
} else if (udv_ptr->udv_value.type == INTGR) {
(void) Gcomplex(&udv_ptr->udv_value, (double) udv_ptr->udv_value.v.int_val, 0.0);
}
return real(&(udv_ptr->udv_value));
}
/* get here => not found */
{
struct value tempval;
(void) Gcomplex(&tempval, value, 0.0);
setvar(varname, tempval);
}
return value;
}
/*****************************************************************
Split Identifier into path and filename
*****************************************************************/
static void splitpath(s, p, f)
char *s;
char *p;
char *f;
{
register char *tmp;
tmp = s + strlen(s) - 1;
while (*tmp != '\\' && *tmp != '/' && *tmp != ':' && tmp - s >= 0)
tmp--;
strcpy(f, tmp + 1);