equatorial_xyz_to_ecliptic_xyz
- ssapy.utils.equatorial_xyz_to_ecliptic_xyz(xq, yq, zq)[source][source]
Convert equatorial rectangular coordinates (X, Y, Z) to ecliptic rectangular coordinates.
This function transforms the position of an object from the equatorial coordinate system to the ecliptic coordinate system using the obliquity of the ecliptic.
Parameters:
xq (float): X-coordinate in the equatorial coordinate system. yq (float): Y-coordinate in the equatorial coordinate system. zq (float): Z-coordinate in the equatorial coordinate system.
Returns:
- tuple: A tuple containing:
xc (float): X-coordinate in the ecliptic coordinate system (unchanged from equatorial X).
yc (float): Y-coordinate in the ecliptic coordinate system.
zc (float): Z-coordinate in the ecliptic coordinate system.
Notes:
The transformation uses the obliquity of the ecliptic (sin_ec and cos_ec) to rotate the Y and Z components.
The obliquity of the ecliptic (sin_ec and cos_ec) must be defined globally or imported prior to calling this function.
Example:
equatorial_xyz_to_ecliptic_xyz(1.0, 0.5, 0.3) -> (xc, yc, zc)