source: Sophya/trunk/SophyaExt/XephemAstroLib/formats.c@ 3632

#include <stdio.h>
#include <math.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>

#include "astro.h"
#include "preferences.h"

/* sprint the variable a in sexagesimal format into out[].
 * w is the number of spaces for the whole part.
 * fracbase is the number of pieces a whole is to broken into; valid options:
 *      360000: <w>:mm:ss.ss
 *      36000:  <w>:mm:ss.s
 *      3600:   <w>:mm:ss
 *      600:    <w>:mm.m
 *      60:     <w>:mm
 * return number of characters written to out, not counting final '\0'.
 */
int
fs_sexa (char *out, double a, int w, int fracbase)
{
        char *out0 = out;
        unsigned long n;
        int d;
        int f;
        int m;
        int s;
        int isneg;

        /* save whether it's negative but do all the rest with a positive */
        isneg = (a < 0);
        if (isneg)
            a = -a;

        /* convert to an integral number of whole portions */
        n = (unsigned long)(a * fracbase + 0.5);
        d = n/fracbase;
        f = n%fracbase;

        /* form the whole part; "negative 0" is a special case */
        if (isneg && d == 0)
            out += sprintf (out, "%*s-0", w-2, "");
        else
            out += sprintf (out, "%*d", w, isneg ? -d : d);

        /* do the rest */
        switch (fracbase) {
        case 60:        /* dd:mm */
            m = f/(fracbase/60);
            out += sprintf (out, ":%02d", m);
            break;
        case 600:       /* dd:mm.m */
            out += sprintf (out, ":%02d.%1d", f/10, f%10);
            break;
        case 3600:      /* dd:mm:ss */
            m = f/(fracbase/60);
            s = f%(fracbase/60);
            out += sprintf (out, ":%02d:%02d", m, s);
            break;
        case 36000:     /* dd:mm:ss.s*/
            m = f/(fracbase/60);
            s = f%(fracbase/60);
            out += sprintf (out, ":%02d:%02d.%1d", m, s/10, s%10);
            break;
        case 360000:    /* dd:mm:ss.ss */
            m = f/(fracbase/60);
            s = f%(fracbase/60);
            out += sprintf (out, ":%02d:%02d.%02d", m, s/100, s%100);
            break;
        default:
            printf ("fs_sexa: unknown fracbase: %d\n", fracbase);
            abort();
        }

        return (out - out0);
}

/* put the given modified Julian date, jd, in out[] according to the given
 * preference format.
 * return number of characters written to out, not counting final '\0'.
 */
int
fs_date (char out[], int format, double jd)
{
        char *out0 = out;
        int m, y;
        double d;

        mjd_cal (jd, &m, &d, &y);
        /* beware of %g rounding day up */
        if ((d < 1.0 && d - floor(d) >= .9999995)
                                    || (d < 10.0 && d - floor(d) >= .999995)
                                    || (d >= 10.0 && d - floor(d) >= .99995))
            mjd_cal (mjd_day(jd+0.5), &m, &d, &y);

        switch (format) {
        case PREF_YMD:
            out += sprintf (out, "%4d/%02d/%02.6g", y, m, d);
            break;
        case PREF_DMY:
            out += sprintf (out, "%2.6g/%02d/%-4d", d, m, y);
            break;
        case PREF_MDY:
            out += sprintf (out, "%2d/%02.6g/%-4d", m, d, y);
            break;
        default:
            printf ("fs_date: bad date pref: %d\n", format);
            abort();
        }

        return (out - out0);
}


/* convert sexagesimal string str AxBxC to double.
 *   x can be anything non-numeric. Any missing A, B or C will be assumed 0.
 *   optional - and + can be anywhere.
 * return 0 if ok, -1 if can't find a thing.
 */
int
f_scansexa (
const char *str0,       /* input string */
double *dp)             /* cracked value, if return 0 */
{
        double a, b, c;
        char str[256];
        char *neg;
        int isneg, r;

        /* copy str0 so we can play with it */
        strncpy (str, str0, sizeof(str)-1);
        str[sizeof(str)-1] = '\0';

        /* note first negative (but not fooled by neg exponent) */
        isneg = 0;
        neg = strchr(str, '-');
        if (neg && (neg == str || (neg[-1] != 'E' && neg[-1] != 'e'))) {
            *neg = ' ';
            isneg = 1;
        }

        /* crack up to three components */
        a = b = c = 0.0;
        r = sscanf (str, "%lf%*[^0-9]%lf%*[^0-9]%lf", &a, &b, &c);
        if (r < 1)
            return (-1);

        /* back to one value, restoring neg */
        *dp = (c/60.0 + b)/60.0 + a;
        if (isneg)
            *dp *= -1;
        return (0);
}

/* crack a floating date string, bp, of the form X/Y/Z determined by the
 *   PREF_DATE_FORMAT preference into its components. allow the day to be a
 *   floating point number,
 * the slashes may also be spaces or colons.
 * a lone component with a decimal point is considered a year.
 */
void
f_sscandate (
char *bp,
int pref,       /* one of PREF_X for PREF_DATE_FORMAT */
int *m,
double *d,
int *y)
{
        double X,Y,Z; /* the three components */
        int n;

        X = Y = Z = 0.0;
        n = sscanf (bp, "%lf%*[/: ]%lf%*[/: ]%lf", &X, &Y, &Z);
        if (n == 1 && (strchr(bp, '.')
                        || (pref == PREF_MDY && (X < 1 || X > 12))
                        || (pref == PREF_DMY && (X < 1 || X > 31)))) {
            double Mjd;
            year_mjd (X, &Mjd);
            mjd_cal (Mjd, m, d, y);
        } else {
            switch (pref) {
            case PREF_MDY:
                if (n > 0 && X != 0)
                    *m = (int)X;
                if (n > 1 && Y != 0)
                    *d = Y;
                if (n > 2 && Z != 0)
                    *y = (int)Z;
                break;
            case PREF_YMD:
                if (n > 0 && X != 0)
                    *y = (int)X;
                if (n > 1 && Y != 0)
                    *m = (int)Y;
                if (n > 2 && Z != 0)
                    *d = Z;
                break;
            case PREF_DMY:
                if (n > 0 && X != 0)
                    *d = X;
                if (n > 1 && Y != 0)
                    *m = (int)Y;
                if (n > 2 && Z != 0)
                    *y = (int)Z;
                break;
            }
        }
}

/* For RCS Only -- Do Not Edit */
static char *rcsid[2] = {(char *)rcsid, "@(#) $RCSfile: formats.c,v $ $Date: 2008-03-25 17:45:14 $ $Revision: 1.7 $ $Name: not supported by cvs2svn $"};