Note
Click here to download the full example code
Re-projecting from CAR to CEA¶
The pfsspy solver takes a cylindrical-equal-area (CEA) projected magnetic field map as input, which is equally spaced in sin(latitude). Some synoptic field maps are equally spaced in latitude however, which is a plate carée (CAR) projection.
This example shows how to use the pfsspy.utils.car_to_cea
function to
reproject a CAR projection to a CEA projection that pfsspy can take as input.
from pfsspy import sample_data
from pfsspy import utils
import matplotlib.pyplot as plt
Load a sample ADAPT map, which has a CAR projection
adapt_maps = utils.load_adapt(sample_data.get_adapt_map())
adapt_map_car = adapt_maps[0]
Out:
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Re-project into a CEA projection
adapt_map_cea = utils.car_to_cea(adapt_map_car)
Out:
/home/docs/checkouts/readthedocs.org/user_builds/pfsspy/envs/0.6.5/lib/python3.7/site-packages/sunpy/map/mapbase.py:871: SunpyUserWarning: Missing metadata for observer: assuming Earth-based observer.
warnings.warn(warning_message, SunpyUserWarning)
/home/docs/checkouts/readthedocs.org/user_builds/pfsspy/envs/0.6.5/lib/python3.7/site-packages/sunpy/map/mapbase.py:871: SunpyUserWarning: Missing metadata for observer: assuming Earth-based observer.
warnings.warn(warning_message, SunpyUserWarning)
/home/docs/checkouts/readthedocs.org/user_builds/pfsspy/envs/0.6.5/lib/python3.7/site-packages/sunpy/map/mapbase.py:871: SunpyUserWarning: Missing metadata for observer: assuming Earth-based observer.
warnings.warn(warning_message, SunpyUserWarning)
Plot the original map and the reprojected map
plt.figure()
adapt_map_car.plot()
plt.figure()
adapt_map_cea.plot()
plt.show()
Out:
/home/docs/checkouts/readthedocs.org/user_builds/pfsspy/envs/0.6.5/lib/python3.7/site-packages/sunpy/map/mapbase.py:871: SunpyUserWarning: Missing metadata for observer: assuming Earth-based observer.
warnings.warn(warning_message, SunpyUserWarning)
/home/docs/checkouts/readthedocs.org/user_builds/pfsspy/envs/0.6.5/lib/python3.7/site-packages/sunpy/map/mapbase.py:871: SunpyUserWarning: Missing metadata for observer: assuming Earth-based observer.
warnings.warn(warning_message, SunpyUserWarning)
Total running time of the script: ( 0 minutes 2.673 seconds)