private ICollection <AstroEvent> FindLunarEclipses(AstroEventsContext context)
{
List <AstroEvent> events = new List <AstroEvent>();
int ln = LunarEphem.Lunation(context.From, LunationSystem.Meeus);
do
{
LunarEclipse eclipse = LunarEclipses.NearestEclipse(ln, next: true);
double jd = eclipse.JulianDayMaximum;
if (jd <= context.To)
{
double jdMax = jd;
string type = Text.Get($"LunarEclipse.Type.{eclipse.EclipseType}");
string phase = Formatters.Phase.Format(eclipse.Magnitude);
var elements = GetLunarEclipseElements(jdMax);
var local = LunarEclipses.LocalCircumstances(eclipse, elements, context.GeoLocation);
string localVisibility = GetLocalVisibilityString(eclipse, local);
events.Add(new AstroEvent(jdMax, Text.Get("LunarEclipse.Event", ("type", type), ("phase", phase), ("localVisibility", localVisibility)), moon));
ln = eclipse.MeeusLunationNumber + 1;
}
else
{
break;
}
}while (true);
return(events);
}
public void FindNearestLunarEclipse()
{
// ex. 54c
{
double jd = new Date(1973, 6, 1).ToJulianDay();
LunarEclipse eclipse = LunarEclipses.NearestEclipse(jd, true);
var d = new Date(eclipse.JulianDayMaximum, 0);
Assert.AreEqual(1973, d.Year);
Assert.AreEqual(6, d.Month);
Assert.AreEqual(15, (int)d.Day);
Assert.AreEqual(20, d.Hour);
Assert.AreEqual(50, d.Minute);
Assert.AreEqual(LunarEclipseType.Penumbral, eclipse.EclipseType);
Assert.AreEqual(0.462, eclipse.Magnitude, 1e-3);
}
// ex. 54d
{
double jd = new Date(1997, 7, 1).ToJulianDay();
int ln = LunarEphem.Lunation(jd, LunationSystem.Meeus);
LunarEclipse eclipse = LunarEclipses.NearestEclipse(ln, true);
var d = new Date(eclipse.JulianDayMaximum, 0);
Assert.AreEqual(1997, d.Year);
Assert.AreEqual(9, d.Month);
Assert.AreEqual(16, (int)d.Day);
Assert.AreEqual(18, d.Hour);
Assert.AreEqual(47, d.Minute);
Assert.AreEqual(LunarEclipseType.Total, eclipse.EclipseType);
Assert.AreEqual(1.187, eclipse.Magnitude, 1e-3);
}
}
/// <inheritdoc />
public LunarEclipse GetNearestLunarEclipse(int ln, bool next, bool saros)
{
return(LunarEclipses.NearestEclipse(ln + (next ? 1 : -1) * (saros ? 223 : 1), next));
}