rtodms.c
1.6 KB
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/* Convert radian argument to DMS ascii format */
#ifndef lint
static const char SCCSID[]="@(#)rtodms.c 4.3 93/06/12 GIE REL";
#endif
#include "projects.h"
#include <stdio.h>
#include <string.h>
/*
** RES is fractional second figures
** RES60 = 60 * RES
** CONV = 180 * 3600 * RES / PI (radians to RES seconds)
*/
static double
RES = 1000.,
RES60 = 60000.,
CONV = 206264806.24709635515796003417;
static char
format[50] = "%dd%d'%.3f\"%c";
static int
dolong = 0;
void
set_rtodms(int fract, int con_w) {
int i;
if (fract >= 0 && fract < 9 ) {
RES = 1.;
/* following not very elegant, but used infrequently */
for (i = 0; i < fract; ++i)
RES *= 10.;
RES60 = RES * 60.;
CONV = 180. * 3600. * RES / PI;
if (! con_w)
(void)sprintf(format,"%%dd%%d'%%.%df\"%%c", fract);
else
(void)sprintf(format,"%%dd%%02d'%%0%d.%df\"%%c",
fract+2+(fract?1:0), fract);
dolong = con_w;
}
}
char *
rtodms(char *s, double r, int pos, int neg) {
int deg, min, sign;
char *ss = s;
double sec;
if (r < 0) {
r = -r;
if (!pos) { *ss++ = '-'; sign = 0; }
else sign = neg;
} else
sign = pos;
r = floor(r * CONV + .5);
sec = fmod(r / RES, 60.);
r = floor(r / RES60);
min = fmod(r, 60.);
r = floor(r / 60.);
deg = r;
if (dolong)
(void)sprintf(ss,format,deg,min,sec,sign);
else if (sec) {
char *p, *q;
(void)sprintf(ss,format,deg,min,sec,sign);
for (q = p = ss + strlen(ss) - (sign ? 3 : 2); *p == '0'; --p) ;
if (*p != '.')
++p;
if (++q != p)
(void)strcpy(p, q);
} else if (min)
(void)sprintf(ss,"%dd%d'%c",deg,min,sign);
else
(void)sprintf(ss,"%dd%c",deg, sign);
return s;
}