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Python: Implemented Rotation_ECL_EQJ.

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Don Cross
2019-12-15 20:41:03 -05:00
parent 126cc04d1d
commit d572edb10f
4 changed files with 102 additions and 0 deletions
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15
source/python/README.md
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@@ -947,6 +947,21 @@ A vector in the orientation specified by `rotation`.
---
<a name="Rotation_ECL_EQJ"></a>
### Rotation_ECL_EQJ()
**Calculates a rotation matrix from ecliptic J2000 (ECL) to equatorial J2000 (EQJ).**
This is one of the family of functions that returns a rotation matrix
for converting from one orientation to another.
Source: ECL = ecliptic system, using equator at J2000 epoch.
Target: EQJ = equatorial system, using equator at J2000 epoch.
### Returns: RotationMatrix
A rotation matrix that converts ECL to EQJ.
---
<a name="Rotation_EQJ_ECL"></a>
### Rotation_EQJ_ECL()

23
source/python/astronomy.py
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@@ -5197,3 +5197,26 @@ def Rotation_EQJ_ECL():
[ 0, +c, -s],
[ 0, +s, +c]
])
def Rotation_ECL_EQJ():
"""Calculates a rotation matrix from ecliptic J2000 (ECL) to equatorial J2000 (EQJ).
This is one of the family of functions that returns a rotation matrix
for converting from one orientation to another.
Source: ECL = ecliptic system, using equator at J2000 epoch.
Target: EQJ = equatorial system, using equator at J2000 epoch.
Returns
-------
RotationMatrix
A rotation matrix that converts ECL to EQJ.
"""
# ob = mean obliquity of the J2000 ecliptic = 0.40909260059599012 radians.
c = 0.9174821430670688 # cos(ob)
s = 0.3977769691083922 # sin(ob)
return RotationMatrix([
[ 1, 0, 0],
[ 0, +c, +s],
[ 0, -s, +c]
])