Ehn/cartopy fan plots

[mts299]

Scope

This PR focuses on using cartopy in pyDARN's plot_fan plots and plot_fov by passing in Projs.GEO_COASTALINE and Coords.GEOGRAPHIC. There is a lot missing nice features but this is the base PR.

Things still to do that are not included in this PR:

• COASTALINE with POLAR coordinates system
• GRID plots
• Convection map plots
• centering based on the radar location
• changing the centering
• plotting on a globe
• etc....

issue: #206

Approval

Number of approvals: 3 approvals if possible

Test

matplotlib version: 3.5.1
Note testers: please indicate what version of matplotlib you are using

import bz2 
import pydarn
import datetime as dt
import matplotlib.pyplot as plt 

pydarn.Fan.plot_fov(stid=65, date=dt.datetime(2022, 1, 8, 14, 5), grid=True, fov_color='blue')#, coords=pydarn.Coords.GEOGRAPHIC ,projs=pydarn.Projs.GEO_COASTALINE)

import bz2 
import pydarn
import datetime as dt
import matplotlib.pyplot as plt 

data_file = "/home/marina/superdarn/data/fitacf/20220108.0801.00.dcn.fitacf.bz2" 

with bz2.open(data_file) as fp: 
    fitacf_stream = fp.read()

data = pydarn.SuperDARNRead(fitacf_stream, True).read_fitacf()

pydarn.Fan.plot_fan(data, grid=True, scan_index=5, fov_color='blue', radar_label=True, groundscatter=True, coords=pydarn.Coords.GEOGRAPHIC, projs=pydarn.Projs.GEO_COASTALINE)
plt.show()

Also test without the coordinate and projection changes and if possible if cartopy is not installed.
You should get the same results in as before without new coordinates and projects and if you don't have cartopy installed and request for a coastaline then it should throw an exception.

[mts299]

@Shirling-VT updated the error message though it will point to the current main page which does not have the install guidelines. I did this so I don't have remember to update it come to release :p

instead are the current ones: https://pydarn.readthedocs.io/en/ehn-cartopy_fan_plots/user/install/

[Shirling-VT]

MacOS 10.15.7
matplotlib 3.4.2
python 3.8.0

Installed cartopy through conda: conda install -c conda-forge cartopy. Other related dependencies (e.g., geos, proj, pyshp, and shapely) are installed automatically with cartopy in conda.

When I ran the plot_fov test code using projs=pydarn.Projs.GEO_COASTALINE, the following error appears:
Traceback (most recent call last):
File "", line 3, in
File "/Users/xueling/opt/anaconda3/envs/pydarn_test/lib/python3.8/enum.py", line 341, in getattr
raise AttributeError(name) from None
AttributeError: GEO_COASTALINE

I checked the pydarn projs.py and found only COASTALINE and POLAR are available. I then changed projs=pydarn.Projs.GEO_COASTALINE to projs=pydarn.Projs.COASTALINE, this error shows up:
Traceback (most recent call last):
File "", line 1, in
File "/Users/xueling/opt/anaconda3/envs/pydarn_test/lib/python3.8/site-packages/pydarn-2.2.1-py3.8.egg/pydarn/plotting/fan.py", line 452, in plot_fov
cls.plot_radar_position(stid, date=date, line_color=line_color,
File "/Users/xueling/opt/anaconda3/envs/pydarn_test/lib/python3.8/site-packages/pydarn-2.2.1-py3.8.egg/pydarn/plotting/fan.py", line 537, in plot_radar_position
plt.scatter(lon, lat, c=line_color, s=5, transform=transform)
File "/Users/xueling/opt/anaconda3/envs/pydarn_test/lib/python3.8/site-packages/matplotlib/pyplot.py", line 3068, in scatter
__ret = gca().scatter(
File "/Users/xueling/opt/anaconda3/envs/pydarn_test/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py", line 305, in wrapper
raise ValueError('Invalid transform: Spherical {} '
ValueError: Invalid transform: Spherical scatter is not supported - consider using PlateCarree/RotatedPole.

When I changed projs=pydarn.Projs.GEO_COASTALINE to projs=pydarn.Projs.POLAR, now I get a figure, which does not look right as well:

Not sure if it's on my side that I didn't install cartopy correctly or needs more dependencies, or if there's something wrong with the test codes. @mts299 Would you mind double checking the test codes?

[mts299]

Thanks @Shirling-VT I may have made minor change that affected everything :(

[mts299]

@Shirling-VT try now, sorry I seem to keep pushing to the wrong cartopy branch

[mts299]

@Shirling-VT nvm looks like there is some other bugs ... @carleyjmartin keeps breaking it

[mts299]

@Shirling-VT Okay now everything should be working:

[mts299]

Please ignore the layering of the grid line and fov_color this has been a known issue just need time to think about it more and will make another PR.

[Shirling-VT]

MacOS 10.15.7
matplotlib 3.4.2
python 3.8.0
conda install -c conda-forge cartopy

Here are my test codes:
import bz2
import pydarn
import datetime as dt
import matplotlib.pyplot as plt

data = pydarn.Fan.plot_fov(stid=65, date=dt.datetime(2022, 1, 8, 14, 5), grid=True,
fov_color='blue', coords=pydarn.Coords.GEOGRAPHIC,
projs=pydarn.Projs.GEO_COASTALINE)
plt.show()

data = pydarn.Fan.plot_fan(fitacf_data, grid=True, scan_index=5, fov_color='blue',
radar_label=True, groundscatter=True,
coords=pydarn.Coords.GEOGRAPHIC, projs=pydarn.Projs.GEO_COASTALINE)
plt.show()

Both plot_fov and plot_fan give me the same error:
Traceback (most recent call last):
File "", line 1, in
File "/Users/xueling/opt/anaconda3/envs/pydarn_test/lib/python3.8/site-packages/pydarn-3.0-py3.8.egg/pydarn/plotting/fan.py", line 471, in plot_fov
cls.plot_radar_position(stid, date=date, line_color=line_color,
File "/Users/xueling/opt/anaconda3/envs/pydarn_test/lib/python3.8/site-packages/pydarn-3.0-py3.8.egg/pydarn/plotting/fan.py", line 556, in plot_radar_position
plt.scatter(lon, lat, c=line_color, s=5, transform=transform)
File "/Users/xueling/opt/anaconda3/envs/pydarn_test/lib/python3.8/site-packages/matplotlib/pyplot.py", line 3068, in scatter
__ret = gca().scatter(
File "/Users/xueling/opt/anaconda3/envs/pydarn_test/lib/python3.8/site-packages/cartopy/mpl/geoaxes.py", line 305, in wrapper
raise ValueError('Invalid transform: Spherical {} '
ValueError: Invalid transform: Spherical scatter is not supported - consider using PlateCarree/RotatedPole.

[mts299]

what is your fitacf data just so I can test it?

[mts299]

Unless you picked some weird data again or not pulling the newest changes... I get no errors :(

The only thing I can think of once again is 3.5.1
That and my cartopy version had be downgraded due to ubuntu being slow on geo packas requirements.
'0.19.0.post1'

@carleyjmartin what are your specs on those two libraries since you use a Mac as well and report no issues with my code?

[carleyjmartin]

macos: 10.15.5
mpl: 3.5.1
python3: 3.9.9
I also installed mpl v3.4.2 and didn't get the above error.
I don't install cartopy with anaconda though, that could be the difference. I install the dependencies in brew and then just pip3 it.
My cartopy is at version 0.20.2

[Shirling-VT]

@mts299 @carleyjmartin Thanks for checking this. I did pull all the newest changes. My cartopy version is 0.18.0. It's very likely that I need to upgrade my cartopy. I remember I saw some posts online mentioning the same issue when using an old version of cartopy. I'll see how I can upgrade it in conda and if I can make it work this time.

[Shirling-VT]

Looks like it's a cartopy issue. I'm able to install version 0.20.2 (conda install -c conda-forge cartopy=0.20.2) and reproduce the plots without any issues:

For some reason, the default installation in conda (maybe my conda is a bit old (4.10.3)?) of cartopy is 0.18.0. I would suggest adding the cartopy verstion requirements (>=0.19.0?) as an installation instruction.

[mts299]

Thank you @Shirling-VT for figuring it out :)

Since its not an actual install in the setup.py where we would force it ... I can make some documentation on it and see if we cna make an exception to also check the version number before a user gets to using it :) I will get this done today!

[mts299]

@Shirling-VT added in the documentation and an exception that is raised if the version is incorrect:

pydarn.exceptions.plot_exceptions.CartopyVersionError: cartopy is independent library that the user mustinstall to use. Please insure the version number is >= 0.19. Your current version is: 0.18.0