private void DoGetPlanetOrbit(PlanetElm planetElm)
{
double ae2 = -2.0 * planetElm.a * planetElm.e;
double t = Math.Sqrt(1.0 - planetElm.e * planetElm.e);
int xp1 = 0;
int xp2 = (this.Division / 2);
int xp3 = (this.Division / 2);
int xp4 = this.Division;
double E = 0.0;
for (int i = 0; i <= (this.Division / 4); i++, E += (360.0 / this.Division))
{
double rcosv = planetElm.a * (UdMath.udcos(E) - planetElm.e);
double rsinv = planetElm.a * t * UdMath.udsin(E);
this.Orbit[xp1++] = new Xyz(rcosv, rsinv, 0.0);
this.Orbit[xp2--] = new Xyz(ae2 - rcosv, rsinv, 0.0);
this.Orbit[xp3++] = new Xyz(ae2 - rcosv, -rsinv, 0.0);
this.Orbit[xp4--] = new Xyz(rcosv, -rsinv, 0.0);
}
}
public PlanetOrbit(int planetNo, ATime atime, int division)
{
this.PlanetNo = planetNo;
this.JD = atime.JD;
this.Division = division;
PlanetElm planetElm = new PlanetElm(planetNo, atime);
this.Orbit = new Xyz[division + 1];
DoGetPlanetOrbit(planetElm);
Matrix vec = Matrix.VectorConstant(planetElm.w * Math.PI / 180.0,
planetElm.N * Math.PI / 180.0,
planetElm.i * Math.PI / 180.0,
atime);
Matrix prec = Matrix.PrecMatrix(atime.JD, 2451512.5);
for (int i = 0; i <= division; i++)
{
this.Orbit[i] = this.Orbit[i].Rotate(vec).Rotate(prec);
}
}
