AttributeError: 'CartesianRepresentation' object has no attribute 'to' (get_body_ephem issue)

🐞 Problem Removal of get_body_ephem leads to issues re: data types (from “Going to Mars” which i was attempting to run as a test)

Because astropy.coordinates.get_body_barycentric_posvel outputs type “CartesianRepresentation” whereas poliastro.ephem.get_body_ephem outputs type “Quantity” (I think…)

Any advice on how to swap the data types? or is there a known fix for this already?

Thank you!

SYSTEM INFO ############################################################################ conda info -a active environment : None user config file : /Users/Jonny/.condarc populated config files : /Users/Jonny/.condarc conda version : 4.4.10 conda-build version : 3.0.27 python version : 3.6.3.final.0 base environment : /anaconda3 (writable) channel URLs : https://repo.continuum.io/pkgs/main/osx-64 https://repo.continuum.io/pkgs/main/noarch https://repo.continuum.io/pkgs/free/osx-64 https://repo.continuum.io/pkgs/free/noarch https://repo.continuum.io/pkgs/r/osx-64 https://repo.continuum.io/pkgs/r/noarch https://repo.continuum.io/pkgs/pro/osx-64 https://repo.continuum.io/pkgs/pro/noarch package cache : /anaconda3/pkgs /Users/Jonny/.conda/pkgs envs directories : /anaconda3/envs /Users/Jonny/.conda/envs platform : osx-64 user-agent : conda/4.4.10 requests/2.18.4 CPython/3.6.3 Darwin/17.5.0 OSX/10.13.4 UID:GID : 501:20 netrc file : None offline mode : False

conda environments:

base * /anaconda3

sys.version: 3.6.3 |Anaconda custom (64-bit)| (defaul… sys.prefix: /anaconda3 sys.executable: /anaconda3/bin/python conda location: /anaconda3/lib/python3.6/site-packages/conda conda-build: /anaconda3/bin/conda-build conda-convert: /anaconda3/bin/conda-convert conda-develop: /anaconda3/bin/conda-develop conda-env: /anaconda3/bin/conda-env conda-index: /anaconda3/bin/conda-index conda-inspect: /anaconda3/bin/conda-inspect conda-metapackage: /anaconda3/bin/conda-metapackage conda-render: /anaconda3/bin/conda-render conda-server: /anaconda3/bin/conda-server conda-skeleton: /anaconda3/bin/conda-skeleton conda-verify: /anaconda3/bin/conda-verify user site dirs:

CIO_TEST: <not set> CONDA_ROOT: /anaconda3 PATH: /anaconda3/bin:/anaconda3/bin:/Library/Frameworks/Python.framework/Versions/3.7/bin://anaconda/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/Library/TeX/texbin REQUESTS_CA_BUNDLE: <not set> SSL_CERT_FILE: <not set>

License directories: /Users/Jonny/.continuum /Users/Jonny/Library/Application Support/Anaconda /anaconda3/licenses License files (license*.txt): Package/feature end dates: ############################################################################

TESTS - Didnt pass them all… ah well ############################################################################

python -c "import poliastro.testing; poliastro.testing.test()" ============================= test session starts ============================== platform darwin – Python 3.6.3, pytest-3.2.1, py-1.4.34, pluggy-0.4.0 rootdir: /anaconda3/lib/python3.6/site-packages/poliastro, inifile: collected 173 items

…/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_bodies.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_coordinates.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_hyper.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_iod.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_jit.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_maneuver.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_patched_conics.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_plotting.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_plotting2d.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_plotting3d.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_stumpff.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_twobody.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/test_util.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/tests_neos/test_dastcom5.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/tests_neos/test_neos_neows.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/tests_twobody/test_angles.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/tests_twobody/test_decorators.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/tests_twobody/test_orbit.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/tests_twobody/test_perturbations.py … …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/tests_twobody/test_propagation.py …xx …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/tests_twobody/test_sample.py …X …/…/anaconda3/lib/python3.6/site-packages/poliastro/tests/tests_twobody/test_states.py …

============== 170 passed, 2 xfailed, 1 xpassed in 73.89 seconds =============== ############################################################################

💡 Possible solutions Reconfigure either poliastro or astropy w.r.t. this issue

Thanks for your help!

[jmerskine1]

Our team have a university (TU Delft) assignment to develop the navigation methods for the LUMIO microsat mission.

https://www.tudelft.nl/en/2018/lr/lumio-the-cubesat-that-will-watch-meteoroid-impacts-on-the-far-side-of-the-moon/

I want to plot the mission using poliastro and show how and where the navigation strategy will operate over the injection, transfer and operational orbit phases (based on the FOV of the onboard camera). Probably a very basic use for poliastro but I’m sure i will find it challenging enough.

[astrojuanlu]

Awesome! Greetings to Prof. Topputo 😃 Please ping me if I can ever help you in any way, and also feel free to join our chat: https://riot.im/app/#/room/#poliastro:matrix.org