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OS/2 Shareware BBS: Science
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sfit110.zip
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DLL
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LORENTZ.C
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C/C++ Source or Header
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1994-11-22
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4KB
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121 lines
#define INCL_WIN
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <os2.h>
#include <float.h>
// the standard number of data columns
#define STDCOL 5
#define XSLOT 0
#define YSLOT 1
#define CALCSLOT -3
#define BESTSLOT -2
#define FLAGSLOT -1
/* static data and parameters */
static double *data; /* start of complete data array */
/* The data is all in a contigous block starting with datx then daty followed by
* zero or more additional data columns as read in from the data file. The last
* three slots are: datt , the current best results and the flag array.
* Each point not in an exclusion zone has its corresponding flag TRUE.
*/
static double *datx; /* x data read in from data file */
static double *daty; /* y data read in from data file */
static double *datt; /* generated data */
static int Ndat; /* number of data points */
static char firsttime;
static double **Ptr; /* pointer to parameter pointer array */
struct info_line
{
char *line;
};
/*****************************************************************************/
/* Do not modify any code not enclosed by this and the end banner */
/*****************************************************************************/
/* the next two values are compared to values passed by the program as check */
/* NADD is the number of additional data columns required for this function */
/* NPARAM is the number of parameters required by this function */
#define NADD 0
#define NPARAM 4
/* edit the following lines or add and delete new lines */
static struct info_line dll_info[] = {
"This function calculates a lorentzian.",
"It requires 3 parameters as follows:",
"P1 is the constant background",
"P2 is the center posiion of lorentzian along the x axis.",
"P3 is the amplitude of lorentzian.",
"P4 is the width of lorentzian.",
NULL};
VOID EXPENTRY fitfunc(void)
{
int i;
double back;
double width;
double amplitude;
double position;
double E;
/* The next section is executed the first time through only */
/* so put any initialization code in here */
if (firsttime)
{
firsttime = FALSE;
/* Mask off all floating point exceptions */
_control87(MCW_EM,MCW_EM);
}
/* give parameters more meaningful names */
back = *Ptr[1];
position = *Ptr[2];
amplitude = *Ptr[3];
width = *Ptr[4];
/* This is the main loop that calculates the function datt[] */
/* for all data points. Put your function in the loop body */
for (i = 0;i < Ndat;i++)
{
E = datx[i] - position;
datt[i] = amplitude / (1 + E*E/width/width) + back; /*Lorentzian */
}
}
/*****************************************************************************/
/* Do not modify any code not enclosed by this and the start banner */
/*****************************************************************************/
char EXPENTRY init_dll_globals(int N,int mb,int NP,double *dat,double *p[])
{
/* set globals */
firsttime = TRUE;
Ndat = N;
if (NADD != mb - STDCOL) return -1;
if (NPARAM != NP) return -2;
/* set array pointers */
data = dat;
daty = dat + N;
datx = dat;
datt = dat + (mb + CALCSLOT) * N; /* the calculated data goes into the third last slot */
/* set parameter pointers */
Ptr = p;
return 0;
}
struct info_line * EXPENTRY get_dll_info(void)
{
/* return pointer to array of info strings set up above */
return dll_info;
}