unify the geometries of COBs in Muller2016

[michaelchin]

Currently, the geometries of COBs in Muller2016 are a mixture of polygons and polylines. The mixture is causing problem when being plotted in GPlately. We need to modify the COBs and make the geometries all polygons(or polylines?).

Thanks to @nickywright for providing us with a code snippet to convert polylines to polygons.

import os.path
import pygplates


input_filenames = [
    'Global_EarthByte_GPlates_PresentDay_StaticPlatePolygons_2019_v1.shp'
]

output_filename_append = '_polygon'

for input_filename in input_filenames:
    # Convert polylines to polygons in the features.
    feature_collection = pygplates.FeatureCollection(input_filename)
    for feature in feature_collection:
        # polygons = [pygplates.PolygonOnSphere(geometry) for geometry in feature.get_geometries()]
        # changed feature get statement to 'all_geometries' - since feature has issues getting different
        # types of geometries
        for geometry in feature.get_all_geometries():
            polygons = pygplates.PolygonOnSphere(geometry)
            feature.set_geometry(polygons)
    
    # Get the output (polygon) filename from the input (polyline) filename.
    input_filename_root, input_filename_ext = os.path.splitext(input_filename)
    output_filename = ''.join((input_filename_root, output_filename_append, input_filename_ext))
    
    # Write the modified feature collection to output file.
    pygplates.FeatureCollection(feature_collection).write(output_filename)

Thanks to @jcannon-gplates for providing valuable suggestion.

basically a pygplates.PolygonOnSphere can take a polyline as a single argument and it’ll convert it (see the second init() listed here). And similarly for converting a polygon (exterior) to a polyline. So if you can get the polyline/polygon into pygplates format then converting is straightforward.

[jcannon-gplates]

I see that it’s been modified to use get_all_geometries () instead of get_geometries() – the only issue might be if have more than one geometry in a single feature - it'll set the last one only. But that should be fine since usually only one geometry per feature anyway.

If it became an issue you could instead have something like:

polygons = [pygplates.PolygonOnSphere(geometry) for geometry in feature.get_all_geometries()]
feature.set_geometry(polygons)

[brmather]

Good pick up, @jcannon-gplates!

[brmather]

Has there been any progress made on this?

[michaelchin]

Has there been any progress made on this?

Can we find a RA to do this?