/// <summary>
/// Converting body's heliocentric coordinates into body's geocentric coordinates
/// This method works only for Mars, Mercury, Jupiter, Venus and Saturn
/// Other planets have their coordinates calculated in geocentric coordinate system already
/// </summary>
/// <param name="bodyId">ID of the celestial body</param>
private void ConvertHeliocentricToGeocentric(int bodyId)
{
if (bodyId <= 1 || bodyId >= 7)
{
return;
}
for (int i = 0; i < PAGE_ITEMS; i++)
{
double longitudalDifference = data[bodyId, i, 0] - data[0, i, 0] - 180;
double geocentricLongitude = data[bodyId, i, 0] + GCMath.arcTan2Deg(GCMath.sinDeg(longitudalDifference), data[bodyId, i, 2] - GCMath.cosDeg(longitudalDifference));
double sx = data[0, i, 2] * GCMath.sinDeg(data[0, i, 0]);
double sy = data[0, i, 2] * GCMath.cosDeg(data[0, i, 0]);
double sz = data[0, i, 2] * GCMath.sinDeg(data[0, i, 1]);
double sq = data[0, i, 2] * GCMath.cosDeg(data[0, i, 1]);
double vx = data[bodyId, i, 2] * GCMath.sinDeg(data[bodyId, i, 0]);
double vy = data[bodyId, i, 2] * GCMath.cosDeg(data[bodyId, i, 0]);
double vz = data[bodyId, i, 2] * GCMath.sinDeg(data[bodyId, i, 1]);
double vq = data[bodyId, i, 2] * GCMath.cosDeg(data[bodyId, i, 1]);
data[bodyId, i, 0] = GCMath.putIn360(geocentricLongitude);
//data[bodyId, i, 0] = GCMath.putIn360(GCMath.arcTan2Deg(sy + vy, sx + vx));
data[bodyId, i, 1] = GCMath.arcTan2Deg(sz + vz, sq + vq);
data[bodyId, i, 2] = Math.Sqrt((sy + vy) * (sy + vy) + (sx + vx) * (sx + vx));
}
}
/// <summary>
///
/// </summary>
/// <param name="y0"></param>
/// <param name="y1"></param>
/// <param name="y2"></param>
/// <param name="y3"></param>
/// <param name="y4"></param>
/// <param name="fraction">fraction added x2, to calculate its y value</param>
/// <returns></returns>
public static double Interpolate(double y1, double y2, double y3, double y4, double y5, double fraction)
{
if ((Math.Abs(y1 - y2) > 300) || (Math.Abs(y2 - y3) > 300) || (Math.Abs(y3 - y4) > 300) || (Math.Abs(y4 - y5) > 300))
{
y1 = GCMath.putIn180(y1);
y2 = GCMath.putIn180(y2);
y3 = GCMath.putIn180(y3);
y4 = GCMath.putIn180(y4);
y5 = GCMath.putIn180(y5);
}
double A = y2 - y1;
double B = y3 - y2;
double C = y4 - y3;
double D = y5 - y4;
double E = B - A;
double F = C - B;
double G = D - C;
double H = F - E;
double J = G - F;
double K = J - H;
double n = fraction;
double n2 = n * n;
double n3 = n2 * n;
double n4 = n2 * n2;
return(y3 + n * ((B + C) / 2 - (H + J) / 12) + n2 * (F / 2 - K / 24) + n3 * ((H + J) / 12) + n4 * K / 24);
}
/// <summary>
/// Converting earth's heliocentric coordinates into sun's geocentric coordinates
/// </summary>
private void ConvertEarthToSun()
{
for (int i = 0; i < PAGE_ITEMS; i++)
{
data[0, i, 0] = GCMath.putIn360(data[0, i, 0] + 180.0);
data[0, i, 1] = -data[0, i, 1];
}
}
/// <summary>
/// Calculates geocentric coordinates for celestial body
/// </summary>
/// <param name="julianDate"></param>
/// <param name="L">Longitude in degrees (0deg to 360deg)</param>
/// <param name="B">Latitude in degrees (-180deg to 180deg)</param>
/// <param name="R">Radius in AU</param>
public static void Calculate(double julianDate, out double L, out double B, out double R)
{
double t = (julianDate - 2451545) / 36525;
double t2 = t * t;
L = GCMath.putIn360(180 + 125.044555 - t * 1934.1361849 + t2 * 0.0020762 + t2 * t / 467410 - t2 * t2 / 60616000);
B = 0.0;
R = 0.3;
}
/// <summary>
///
/// </summary>
/// <param name="bodyId">0 - sun, 1-moon, 2-mars, 3-mercury, 4-jupiter, 5-venus, 6-saturn, 7-rahu, 8-ketu, 9-ascendant</param>
/// <param name="julianDate"></param>
/// <param name="L">Longitude in degrees</param>
/// <param name="B">Latitude in degrees</param>
/// <param name="R">Radius in AU</param>
public static void GetGeocentricCoordinates(int bodyId, double julianDate, out double L, out double B, out double R)
{
// for sun and moon calculate always fresh values
if (bodyId == 0)
{
GCEarth.Calculate(julianDate, out L, out B, out R);
L = GCMath.putIn360(L + 180);
B = -B;
return;
}
else if (bodyId == 1)
{
GCMoonData.Calculate(julianDate, out L, out B, out R);
return;
}
else
{
GCAstronomyCoordPage page = null;
int b = Convert.ToInt32(Math.Floor(julianDate));
int a = b / GCAstronomyCoordPage.PAGE_SIZE;
int Base = a * GCAstronomyCoordPage.PAGE_SIZE;
int Index = b - Base + GCAstronomyCoordPage.PAGE_HEAD;
double fraction = julianDate - b;
if (pages.ContainsKey(a))
{
page = pages[a];
}
else
{
page = new GCAstronomyCoordPage(Base);
pages.Add(a, page);
}
if (!page.dataInit[bodyId])
{
page.InitializePlanet(bodyId);
}
L = GCMath.putIn360(Interpolate(page.data[bodyId, Index - 2, 0],
page.data[bodyId, Index - 1, 0], page.data[bodyId, Index, 0],
page.data[bodyId, Index + 1, 0], page.data[bodyId, Index + 2, 0], fraction));
B = Interpolate(page.data[bodyId, Index - 2, 1],
page.data[bodyId, Index - 1, 1], page.data[bodyId, Index, 1],
page.data[bodyId, Index + 1, 1], page.data[bodyId, Index + 2, 1], fraction);
R = Interpolate(page.data[bodyId, Index - 2, 2],
page.data[bodyId, Index - 1, 2], page.data[bodyId, Index, 2],
page.data[bodyId, Index + 1, 2], page.data[bodyId, Index + 2, 2], fraction);
}
}
public static double GetRawLongitude(int bodyId, int julianDay)
{
double L, B, R;
// for sun and moon calculate always fresh values
if (bodyId == 0)
{
GCEarth.Calculate(julianDay, out L, out B, out R);
return(GCMath.putIn360(L + 180));
}
else if (bodyId == 1)
{
GCMoonData.Calculate(julianDay, out L, out B, out R);
return(L);
}
else
{
GCAstronomyCoordPage page = null;
int b = julianDay;
int a = b / GCAstronomyCoordPage.PAGE_SIZE;
int Base = a * GCAstronomyCoordPage.PAGE_SIZE;
int Index = b - Base + GCAstronomyCoordPage.PAGE_HEAD;
if (pages.ContainsKey(a))
{
page = pages[a];
}
else
{
page = new GCAstronomyCoordPage(Base);
pages.Add(a, page);
}
if (!page.dataInit[bodyId])
{
page.InitializePlanet(bodyId);
}
return(page.data[bodyId, Index, 0]);
}
}
