void
sun_times_init(void)
{
struct tm *tm = &pikrellcam.tm_local;
int n, year, month, mday;
if ( sscanf(pikrellcam.latitude, "%lf", &sun.latitude) == 1
&& sscanf(pikrellcam.longitude, "%lf", &sun.longitude) == 1
)
{
n = strlen(pikrellcam.latitude);
if (pikrellcam.latitude[n - 1] == 'S' || pikrellcam.latitude[n - 1] == 's')
sun.latitude = -sun.latitude;
n = strlen(pikrellcam.longitude);
if (pikrellcam.longitude[n - 1] == 'W' || pikrellcam.longitude[n - 1] == 'w')
sun.longitude = -sun.longitude;
year = tm->tm_year + 1900;
month = tm->tm_mon + 1;
mday = tm->tm_mday + 1;
sun.sun_valid = sun_rise_set(year, month, mday,
sun.longitude, sun.latitude,
&sun.d_sunrise, &sun.d_sunset);
sun.civil_valid = civil_twilight(year, month, mday,
sun.longitude, sun.latitude,
&sun.d_dawn, &sun.d_dusk);
sun.nautical_valid = nautical_twilight(year, month, mday,
sun.longitude, sun.latitude,
&sun.d_nautical_dawn, &sun.d_nautical_dusk);
sun.d_sunrise = TMOD(sun.d_sunrise + tm->tm_gmtoff / 3600);
sun.sunrise = sun.d_sunrise * 60;
sun.d_sunset = TMOD(sun.d_sunset + tm->tm_gmtoff / 3600);
sun.sunset = sun.d_sunset * 60;
sun.d_dawn = TMOD(sun.d_dawn + tm->tm_gmtoff / 3600);
sun.dawn = sun.d_dawn * 60;
sun.d_dusk = TMOD(sun.d_dusk + tm->tm_gmtoff / 3600);
sun.dusk = sun.d_dusk * 60;
sun.d_nautical_dawn = TMOD(sun.d_nautical_dawn + tm->tm_gmtoff / 3600);
sun.nautical_dawn = sun.d_nautical_dawn * 60;
sun.d_nautical_dusk = TMOD(sun.d_nautical_dusk + tm->tm_gmtoff / 3600);
sun.nautical_dusk = sun.d_nautical_dusk * 60;
log_printf_no_timestamp("sunrise/sunset times: %s dawn/dusk times: %s\n",
sun.sun_valid ? "invalid" : "valid",
sun.civil_valid ? "invalid" : "valid");
log_printf_no_timestamp(" dawn: %d:%02d\n", sun.dawn / 60, sun.dawn % 60);
log_printf_no_timestamp(" sunrise: %d:%02d\n", sun.sunrise / 60, sun.sunrise % 60);
log_printf_no_timestamp(" sunset: %d:%02d\n", sun.sunset / 60, sun.sunset % 60);
log_printf_no_timestamp(" dusk: %d:%02d\n", sun.dusk / 60, sun.dusk % 60);
}
}
std::tuple<Time,Time,bool> sunriset_today(void)
{
double lon = 25.183, lat = 61.567;
std::time_t now = time(0);
std::tm tm = *localtime(&now);
int year = 1900 + tm.tm_year, mon = tm.tm_mon + 1, day = tm.tm_mday;
double rise, set;
bool rs;
int zo = zone_utc_plus();
rs = (bool) sun_rise_set(year, mon, day, lon, lat, &rise, &set);
Time r, s;
if(rs == 0) {
rise += zo; set += zo;
if(set>24) set -= 24;
r = Time(rise*3600);
s = Time(set*3600);
} else { //yoton yo
r = Time(0);
s = Time(0);
}
return std::make_tuple(r,s,rs);
}
int main(int argc, char *argv[])
{
int i, j;
int year,month,day;
double lon = -77.06945;
double lat = 38.794433;
int coords_set = 0;
double temp;
int local = 1;
int hemisphere;
int mode = MODE_USAGE;
int offset_hour = 0;
int offset_min = 0;
int offset_sec = 0;
int verbose = 0;
time_t tt;
struct tm *tm;
tt = time(NULL);
ctime(&tt);
tm = localtime(&tt);
year = 1900 + tm->tm_year;
month = 1+ tm->tm_mon;
day = 1+ tm->tm_mday;
timezone_name = tm->tm_zone;
timezone_offset = tm->tm_gmtoff;
for (i=1; i< argc; i++) {
if (!strcmp("-V", argv[i])) {
printf("sunwait version 0.1\n");
exit(0);
}
if (!strcmp("-z", argv[i])) {
local = 0;
}
if (!strcmp("-h", argv[i])) {
print_usage();
exit(0);
}
if (!strcmp("-v", argv[i])) {
verbose++;
}
if (!strcmp("-p", argv[i])) {
mode = MODE_PRINT;
}
if (!strcmp("-y", argv[i])) {
i++;
year = atoi(argv[i]);
}
if (!strcmp("-m", argv[i])) {
i++;
month = atoi(argv[i]);
}
if (!strcmp("-d", argv[i])) {
i++;
day = 1 + atoi(argv[i]);
}
if (2 == sscanf(argv[i], "%lf%1[Nn]", &temp, &hemisphere)) {
lat = temp;
coords_set |= LAT_SET;
}
if (2 == sscanf(argv[i], "%lf%1[Ss]", &temp, &hemisphere)) {
lat = -temp;
coords_set |= LAT_SET;
}
if (2 == sscanf(argv[i], "%lf%1[Ww]", &temp, &hemisphere)) {
lon = -temp;
coords_set |= LON_SET;
}
/* this looks different from the others because 77E
parses as scientific notation */
if (1 == sscanf(argv[i], "%lf%", &temp, &hemisphere)
&& (argv[i][strlen(argv[i])-1] == 'E' ||
argv[i][strlen(argv[i])-1] == 'e')) {
lon = temp;
coords_set |= LON_SET;
}
for (j=0; options[j].label; j++) {
if (strstr(argv[i], options[j].label)) {
mode = (mode &~ options[j].mask) | options[j].value;
}
}
if (('+' == argv[i][0] || '-' == argv[i][0]) &&
('0' <= argv[i][1] && '9' >= argv[i][1])) {
/* perl would be nice here */
char* temp;
temp = 1+argv[i];
offset_min = strtol(temp, &temp, 10);
if (':' == *temp) {
offset_hour = offset_min;
offset_min = strtol(temp+1, &temp, 10);
}
if (':' == *temp) {
offset_sec = strtol(temp+1, &temp, 10);
}
if ('-' == argv[i][0]) {
offset_hour *= -1;
offset_min *= -1;
offset_sec *= -1;
}
}
}
if (coords_set != (LAT_SET | LON_SET)) {
fprintf(stderr, "warning: latitude or longitude not set\n\tdefault coords of Alexandria, Virgina, USA used\n");
}
if ((mode & MODE_MASK) && (mode & EVENT_MASK)) {
int sit;
double up, down, now, interval, offset;
switch (mode & MODE_MASK) {
case MODE_USAGE:
print_usage();
exit(0);
break;
case MODE_SUN:
sit = sun_rise_set ( year, month, day, lon, lat,
&up, &down );
break;
case MODE_CIVIL:
sit = civil_twilight ( year, month, day, lon, lat,
&up, &down );
break;
case MODE_NAUT:
sit = nautical_twilight ( year, month, day, lon, lat,
&up, &down );
break;
case MODE_ASTR:
sit = astronomical_twilight( year, month, day, lon, lat,
&up, &down );
break;
}
if (0 != sit) {
fprintf(stderr, "Event does not occur today\n");
exit(1);
}
up = TMOD(up+timezone_offset/3600);
down = TMOD(down+timezone_offset/3600);
now = tm->tm_hour/1.0 + tm->tm_min/60.0 + tm->tm_sec/3600.0;
offset = offset_hour/1.0 + offset_min/60.0 + offset_sec/3600.0;
if (EVENT_RISE == (mode & EVENT_MASK)) {
printf("%2.2d:%2.2d\n", HOURS(up+offset), MINUTES(up+offset));
} else if (EVENT_SET == (mode & EVENT_MASK)){
printf("%2.2d:%2.2d\n", HOURS(down+offset), MINUTES(down+offset));
} else { /* mode is EVENT_STATE */
if(now>up && now<down) {
printf("up\n");
} else {
printf("down\n");
}
}
if (0 > interval) {
if (0 < verbose) {
fprintf(stderr, "Warning: event already passed for today, waiting till tomorrow.\n");
}
}
if (1 < verbose) {
fprintf(stderr, "Up %f\n", up);
fprintf(stderr, "Down %f\n", down);
fprintf(stderr, "Now %f\n", now);
fprintf(stderr, "Offset %f\n", offset);
}
}
if (MODE_PRINT == (MODE_MASK & mode))
print_everything(year, month, day, lat, lon, tm, local);
if (MODE_USAGE == (MODE_MASK & mode))
print_usage();
exit(0);
}
void TimeRange::computeSunSetRise(int year, int month, int day,
int &rise_hour, int &rise_min,
int &set_hour, int &set_min)
{
if (year == cyear && month == cmonth && day == cday &&
(sunrise_hour_cache != 0 || sunrise_min_cache != 0 ||
sunset_hour_cache != 0 || sunset_min_cache != 0))
{
rise_hour = sunrise_hour_cache;
rise_min = sunrise_min_cache;
set_hour = sunset_hour_cache;
set_min = sunset_min_cache;
return;
}
double longitude;
double latitude;
Params opt;
get_config_options(opt);
if (!opt.Exists("longitude") || !opt.Exists("latitude"))
{
longitude = 2.548828;
latitude = 46.422713;
cError() << "Horaire: To use sunset/sunrise, you have to set your longitude/latitude in configuration!";
cError() << "Horaire: Please go to the webpage of the server to set these parameters.";
}
else
{
from_string(get_config_option("longitude"), longitude);
from_string(get_config_option("latitude"), latitude);
}
double rise, set;
int res;
cInfo() << "Horaire: Computing sunrise/sunset for date " <<
day << "/" << month << "/" << year;
res = sun_rise_set(year, month, day, longitude, latitude, &rise, &set);
if (res != 0)
{
rise_hour = 0;
rise_min = 0;
set_hour = 0;
set_min = 0;
cError() << "Horaire: Error in sunset/sunrise calculation!";
return;
}
long tzOffset = getTimezoneOffset();
rise_min = minutes(rise + minutes((double)tzOffset / 3600.0));
rise_hour = hours(rise + (double)tzOffset / 3600.0);
set_min = minutes(set + minutes((double)tzOffset / 3600.0));
set_hour = hours(set + (double)tzOffset / 3600.0);
std::stringstream streamrise, streamset;
streamrise << std::setfill('0') << std::setw(2) << rise_hour << ":" << rise_min;
streamset << std::setfill('0') << std::setw(2) << set_hour << ":" << set_min;
cInfo() << "Horaire: sunrise is at " << streamrise.str() << " and sunset is at " <<
streamset.str();
sunrise_hour_cache = rise_hour;
sunrise_min_cache = rise_min;
sunset_hour_cache = set_hour;
sunset_min_cache = set_min;
cyear = year;
cmonth = month;
cday = day;
}
/**
Return the local brightness value.
This function uses sunriset.h to calculate sunrise, sunset, and civil
twilight times.
@param[in] lat The latitude of the current location.
@param[in] lon The longitude of the current location.
@return Returns 0 for night, 1 for twilight, or 2 for day, depending on
local time. Returns -1 if brightness could not be determined.
*/
int get_local_brightness(double lat, double lon) {
struct tm ltime;
time_t now;
double htime, sunrise, sunset, civ_start, civ_end;
int year, month, day, gmt_offset_h, rs, civ;
char sr_s[6], ss_s[6], civ_start_s[6], civ_end_s[6];
time(&now);
localtime_r(&now, <ime);
year = ltime.tm_year + 1900;
month = ltime.tm_mon + 1;
day = ltime.tm_mday;
/* GMT offset in hours with local time zone */
gmt_offset_h = ltime.tm_gmtoff / 3600;
/* Current time in hours */
htime = (double)ltime.tm_hour + (double)ltime.tm_min / 60.0;
/* Set local sunrise, sunset, and civil twilight times */
rs = sun_rise_set(year, month, day, lon, lat, &sunrise, &sunset);
civ = civil_twilight(year, month, day, lon, lat, &civ_start, &civ_end);
switch (rs) {
case 0:
sunrise += gmt_offset_h;
sunset += gmt_offset_h;
eprintf("Sun rises %s, sets %s %s\n", hours_to_hm(sunrise, sr_s),
hours_to_hm(sunset, ss_s), ltime.tm_zone);
break;
case +1:
eprintf("Sun above horizon\n");
return 2;
break;
case -1:
eprintf("Sun below horizon\n");
return 0;
break;
}
switch (civ) {
case 0:
civ_start += gmt_offset_h;
civ_end += gmt_offset_h;
eprintf("Civil twilight starts %s, ends %s %s\n",
hours_to_hm(civ_start, civ_start_s),
hours_to_hm(civ_end, civ_end_s), ltime.tm_zone);
break;
case +1:
eprintf("Never darker than civil twilight\n");
break;
case -1:
eprintf("Never as bright as civil twilight\n");
break;
}
if (rs == 0 && civ == 0) {
if (sunrise < htime && htime < sunset)
return 2;
else if (htime < civ_start || htime > civ_end)
return 0;
else
return 1;
}
else {
return -1;
}
}
int main(int argc, char *argv[]) {
double lon;
double lat;
int year,month,day;
int offset_min,duration;
int sit;
char* durationFile;
double up, down, now, interval, offset;
time_t tt;
struct tm *tm;
/* 5 inputs plus the command is needed to run */
if(argc!=5) {
print_usage();
exit(-1);
}
while (1) {
tt = time(NULL);
ctime(&tt);
tm = localtime(&tt);
/* get inputs passed in via command line */
lat=strtod(argv[1],NULL);
lon=strtod(argv[2],NULL);
offset_min=atoi(argv[3]);
durationFile=argv[4];
/* Setup time */
year = 1900 + tm->tm_year;
month = 1+ tm->tm_mon;
day = 1+ tm->tm_mday;
timezone_name = tm->tm_zone;
timezone_offset = tm->tm_gmtoff;
/* get sunrise and sunset values */
sit = sun_rise_set( year, month, day, lon, lat, &up, &down );
up = TMOD(up+timezone_offset/3600);
down = TMOD(down+timezone_offset/3600);
printf ("==> Sunrise: %5.2f, Sunset: %5.2f GMT\n", up, down);
printf("get Duration values from file %s \n",durationFile);
duration=getDurationByMonth(month,durationFile);
if (0 != sit) {
fprintf(stderr, "Event does not occur today\n");
exit(1);
}
now = tm->tm_hour/1.0 + tm->tm_min/60.0 + tm->tm_sec/3600.0;
offset = offset_min/60.0;
interval = down - now + offset;
if (0 > interval) {
printf("==>Sunset has occured today %5.2f hours ago\n",interval);
if (interval+(duration/60)>0 ) {
duration=duration+(interval*60);
printf("Can wait %i minutes\n",duration);
}
else interval=interval+24.0;
}
printf ("==> Hours to Wait: %5.2f \n", interval);
delay((unsigned int)(interval*3600.0*1000));
/* do */
turnOnZone(duration,pin);
printf("==>SUNLIGHTS program complete for today");
}
}
main()
{
int year,month,day;
double lon, lat;
double daylen, civlen, nautlen, astrlen;
double rise, set, civ_start, civ_end, naut_start, naut_end,
astr_start, astr_end;
double daylen_int,daylen_frac; /* CWR */
int rs, civ, naut, astr;
int daylen_hours,daylen_min, gmtoff_hr; /* cwr */
double rise_int,rise_frac,set_int,set_frac;
int rise_hours,rise_min,set_hours,set_min;
time_t the_time; /* only need so can get time zone of local machine... */
struct tm *mylocal_time;
char buf[80];
/* get time and offset from GMT */
time(&the_time);
mylocal_time = localtime(&the_time);
gmtoff_hr = mylocal_time->tm_gmtoff/3600;
printf("Enter longitude and latitude in decimal degrees, i.e. -97.75 30.23\n");
printf("Hint: divide minutes by 60 to get decimal portion\n");
printf( "Longitude (+ is east) and latitude (+ is north) : " );
fgets(buf, 80, stdin);
sscanf(buf, "%lf %lf", &lon, &lat );
for(;;)
{
printf( "Input date ( yyyy mm dd ) (ctrl-C exits): " );
fgets(buf, 80, stdin);
sscanf(buf, "%d %d %d", &year, &month, &day );
daylen = day_length(year,month,day,lon,lat);
civlen = day_civil_twilight_length(year,month,day,lon,lat);
nautlen = day_nautical_twilight_length(year,month,day,lon,lat);
astrlen = day_astronomical_twilight_length(year,month,day,
lon,lat);
daylen_frac = modf(daylen,&daylen_int); /* daylen into int and fraction */
daylen_hours = (int)daylen_int;
daylen_min = (int)(daylen_frac * 60);
printf( "Day length: %5.2f hours", daylen );
printf( "(%2d hours %2d min)\n", daylen_hours,daylen_min );
daylen_frac = modf(civlen,&daylen_int);
daylen_hours = (int)daylen_int;
daylen_min = (int)(daylen_frac * 60);
printf( "With civil twilight %5.2f hours", civlen );
printf( "(%2d hours %2d min)\n", daylen_hours,daylen_min );
daylen_frac = modf(nautlen,&daylen_int);
daylen_hours = (int)daylen_int;
daylen_min = (int)(daylen_frac * 60);
printf( "With nautical twilight %5.2f hours", nautlen );
printf( "(%2d hours %2d min)\n", daylen_hours,daylen_min );
daylen_frac = modf(astrlen,&daylen_int);
daylen_hours = (int)daylen_int;
daylen_min = (int)(daylen_frac * 60);
printf( "With astronomical twilight %5.2f hours", astrlen );
printf( "(%2d hours %2d min)\n", daylen_hours,daylen_min );
daylen_frac = modf((civlen-daylen)/2.0,&daylen_int);
daylen_hours = (int)daylen_int;
daylen_min = (int)(daylen_frac * 60);
printf( "Length of twilight: civil %5.2f hours",
(civlen-daylen)/2.0);
printf( "(%2d hours %2d min)\n", daylen_hours,daylen_min );
daylen_frac = modf((nautlen-daylen)/2.0,&daylen_int);
daylen_hours = (int)daylen_int;
daylen_min = (int)(daylen_frac * 60);
printf( " nautical %5.2f hours",
(nautlen-daylen)/2.0);
printf( "(%2d hours %2d min)\n", daylen_hours,daylen_min );
daylen_frac = modf((astrlen-daylen)/2.0,&daylen_int);
daylen_hours = (int)daylen_int;
daylen_min = (int)(daylen_frac * 60);
printf( " astronomical %5.2f hours",
(astrlen-daylen)/2.0);
printf( "(%2d hours %2d min)\n", daylen_hours,daylen_min );
rs = sun_rise_set ( year, month, day, lon, lat,
&rise, &set );
civ = civil_twilight ( year, month, day, lon, lat,
&civ_start, &civ_end );
naut = nautical_twilight ( year, month, day, lon, lat,
&naut_start, &naut_end );
astr = astronomical_twilight( year, month, day, lon, lat,
&astr_start, &astr_end );
daylen_frac = modf(((rise+set)/2.0)+gmtoff_hr ,&daylen_int);
daylen_hours = (int)daylen_int;
daylen_min = (int)(daylen_frac * 60);
printf( "Sun at south %5.2fh UT,%20d:%02d local\n", (rise+set)/2.0,daylen_hours,daylen_min);
switch( rs )
{
case 0:
/* add minutes and local. CWR*/
rise_frac = modf(rise+gmtoff_hr ,&rise_int);
rise_hours = (int)rise_int;
rise_min = (int)(rise_frac * 60);
set_frac = modf(set+gmtoff_hr ,&set_int);
set_hours = (int)set_int;
set_min = (int)(set_frac * 60);
printf( "Sun rises %5.2fh UT, sets %5.2fh UT;\n rises %02d:%02d, sets %02d:%02d local\n",
rise, set, rise_hours,rise_min,set_hours,set_min);
break;
case +1:
printf( "Sun above horizon\n" );
break;
case -1:
printf( "Sun below horizon\n" );
break;
}
switch( civ )
{
case 0:
rise_frac = modf(civ_start+gmtoff_hr ,&rise_int);
rise_hours = (int)rise_int;
rise_min = (int)(rise_frac * 60);
set_frac = modf(civ_end+gmtoff_hr ,&set_int);
set_hours = (int)set_int;
set_min = (int)(set_frac * 60);
printf( "Civil twilight starts %5.2fh, "
"ends %5.2fh UT;\n starts %02d:%02d, ends %02d:%02d local\n",
civ_start, civ_end,
rise_hours, rise_min, set_hours, set_min);
break;
case +1:
printf( "Never darker than civil twilight\n" );
break;
case -1:
printf( "Never as bright as civil twilight\n" );
break;
}
switch( naut )
{
case 0:
rise_frac = modf(naut_start+gmtoff_hr ,&rise_int);
rise_hours = (int)rise_int;
rise_min = (int)(rise_frac * 60);
set_frac = modf(naut_end+gmtoff_hr ,&set_int);
set_hours = (int)set_int;
set_min = (int)(set_frac * 60);
printf( "Nautical twilight starts %5.2fh, "
"ends %5.2fh UT;\n starts %02d:%02d, ends %02d:%02d local\n",
naut_start, naut_end,
rise_hours, rise_min, set_hours, set_min );
break;
case +1:
printf( "Never darker than nautical twilight\n" );
break;
case -1:
printf( "Never as bright as nautical twilight\n" );
break;
}
switch( astr )
{
case 0:
rise_frac = modf(astr_start+gmtoff_hr ,&rise_int);
rise_hours = (int)rise_int;
rise_min = (int)(rise_frac * 60);
set_frac = modf(astr_end+gmtoff_hr ,&set_int);
set_hours = (int)set_int;
set_min = (int)(set_frac * 60);
printf( "Astronomical twilight starts %5.2fh, "
"ends %5.2fh UT;\n starts %02d:%02d, ends %02d:%02d local\n",
astr_start, astr_end,
rise_hours, rise_min, set_hours, set_min );
break;
case +1:
printf( "Never darker than astronomical twilight\n" );
break;
case -1:
printf( "Never as bright as astronomical twilight\n" );
break;
}
return 0;
}
}
main()
{
int year,month,day;
double lon, lat;
double daylen, civlen, nautlen, astrlen;
double rise, set, civ_start, civ_end, naut_start, naut_end,
astr_start, astr_end;
int rs, civ, naut, astr;
char buf[80];
printf( "Longitude (+ is east) and latitude (+ is north) : " );
fgets(buf, 80, stdin);
sscanf(buf, "%lf %lf", &lon, &lat );
for(;;)
{
printf( "Input date ( yyyy mm dd ) (ctrl-C exits): " );
fgets(buf, 80, stdin);
sscanf(buf, "%d %d %d", &year, &month, &day );
daylen = day_length(year,month,day,lon,lat);
civlen = day_civil_twilight_length(year,month,day,lon,lat);
nautlen = day_nautical_twilight_length(year,month,day,lon,lat);
astrlen = day_astronomical_twilight_length(year,month,day,
lon,lat);
printf( "Day length: %5.2f hours\n", daylen );
printf( "With civil twilight %5.2f hours\n", civlen );
printf( "With nautical twilight %5.2f hours\n", nautlen );
printf( "With astronomical twilight %5.2f hours\n", astrlen );
printf( "Length of twilight: civil %5.2f hours\n",
(civlen-daylen)/2.0);
printf( " nautical %5.2f hours\n",
(nautlen-daylen)/2.0);
printf( " astronomical %5.2f hours\n",
(astrlen-daylen)/2.0);
rs = sun_rise_set ( year, month, day, lon, lat,
&rise, &set );
civ = civil_twilight ( year, month, day, lon, lat,
&civ_start, &civ_end );
naut = nautical_twilight ( year, month, day, lon, lat,
&naut_start, &naut_end );
astr = astronomical_twilight( year, month, day, lon, lat,
&astr_start, &astr_end );
printf( "Sun at south %5.2fh UT\n", (rise+set)/2.0 );
switch( rs )
{
case 0:
printf( "Sun rises %5.2fh UT, sets %5.2fh UT\n",
rise, set );
break;
case +1:
printf( "Sun above horizon\n" );
break;
case -1:
printf( "Sun below horizon\n" );
break;
}
switch( civ )
{
case 0:
printf( "Civil twilight starts %5.2fh, "
"ends %5.2fh UT\n", civ_start, civ_end );
break;
case +1:
printf( "Never darker than civil twilight\n" );
break;
case -1:
printf( "Never as bright as civil twilight\n" );
break;
}
switch( naut )
{
case 0:
printf( "Nautical twilight starts %5.2fh, "
"ends %5.2fh UT\n", naut_start, naut_end );
break;
case +1:
printf( "Never darker than nautical twilight\n" );
break;
case -1:
printf( "Never as bright as nautical twilight\n" );
break;
}
switch( astr )
{
case 0:
printf( "Astronomical twilight starts %5.2fh, "
"ends %5.2fh UT\n", astr_start, astr_end );
break;
case +1:
printf( "Never darker than astronomical twilight\n" );
break;
case -1:
printf( "Never as bright as astronomical twilight\n" );
break;
}
return 0;
}
}
int
main (void)
{
int year, month, day;
double lon, lat;
double len, rise, set, cur_time;
int rc;
char ch;
time_t t;
struct tm *tm;
t = time (NULL);
tm = gmtime (&t);
lon = 0;
sun_rise_set (tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
lon, 0.0, &rise, &set);
cur_time = tm->tm_hour + tm->tm_min / 60.0;
lon += (rise - cur_time) * 15.0;
if (lon > 180.0)
lon -= 360.0;
if (lon < -180.0)
lon += 360.0;
printf ("==> Sun is rising at longitude %5.2fE, latitude 0.00N\n", lon);
printf ("Longitude (+ is east) and latitude (+ is north), or * for Lugano: ");
ch = getchar ();
if (ch == '*')
lon = 8.0 + 57.0/60.0, lat = 46.0;
else
{
ungetc (ch, stdin);
while (scanf ("%lf %lf", &lon, &lat) < 2)
;
}
tm = localtime (&t);
year = tm->tm_year + 1900;
month = tm->tm_mon + 1;
day = tm->tm_mday;
do
{
len = day_length (year, month, day, lon, lat);
printf ("==> Day length: %5.2f hours\n", len);
rc = sun_rise_set (year, month, day, lon, lat, &rise, &set);
if (rc == 1)
printf ("==> Sun never sets!\n");
else if (rc == -1)
printf ("==> Sun never rises!\n");
else
{
printf ("==> Midday: %5.2f GMT\n", (rise + set) / 2);
printf ("==> Sunrise: %5.2f, Sunset: %5.2f GMT\n", rise, set);
}
rc = civil_rise_set (year, month, day, lon, lat, &rise, &set);
if (rc == 1)
printf ("==> Sun never reaches civil dusk!\n");
else if (rc == -1)
printf ("==> Sun never reaches civil dawn!\n");
else
printf ("==> Civil sunrise: %5.2f, Sunset: %5.2f GMT\n", rise, set);
printf ("Date (yyyy mm dd) (ctrl-C exits): ");
while (scanf ("%d %d %d", &year, &month, &day) < 3 && !feof (stdin))
;
}
while (!feof (stdin));
return 0;
}
