Processing TFCat Objects
TFCat objects have been designed out of the GeoJSON specification, replacing the geographic coordinates with temporal-spectral coordinates. So apart from the CRS (Coordinate Reference System), the content of the TFCat JSON files are compliant with the GeoJSON specification. Geometry management tools applicable to GeoJSON geometries can thus be used, such as shapely, as shown below.
Using shapely
The shapely library offers a very well developed set of tools for managing geometries, including transformations, conversions, operations, etc.
In the small code example below, we load a catalogue containing MultiPoint features, and compute the convex hull surrounding the feature.
from tfcat import TFCat
from shapely.geometry import shape
tf_url = 'https://maser.obspm.fr/doi/10.25935/r11g-6j63/content/cassini_faraday_patches_2006.json'
cat = TFCat.from_url(tf_url)
event = shape(cat.feature(0).geometry)
hull = event.convex_hull
from matplotlib import pyplot as plt
plt.plot(*list(zip(*[item.coords.xy for item in event.geoms])), '+')
plt.plot(*hull.exterior.xy, '--')
plt.xlabel(cat.crs.time_label)
plt.ylabel(cat.crs.spectral_label)
plt.show()
More examples
Examples are provides on Jupyter notebooks. Links to executable notebooks are provided therein for testing purposes.