ENH: bounds function

[jorisvandenbossche]

Shapely has a bounds attribute, implemented at:

https://github.com/Toblerity/Shapely/blob/803b21bb87f3f76ce25bec4e015b46038c0df1f4/shapely/coords.py#L159-L186

I personally find this a useful operation that I use regularly. You can already get the coordinates per geometry and calculate the min/max of this, but doing that on an array of geometries still requires some manual looping.

Something to add to pygeos?

[jorisvandenbossche]

Postgis seems to have something related: ST_Extent (https://postgis.net/docs/ST_Extent.html). But this returns a "BOX" object instead of the 4 values as bounds does. And it is also an aggregation function (so it typically creates the bounding box of multiple geometries, I suppose, similarly to the total_bounds in GeoPandas)

The "spatial" equivalent is actually the pygeos.envelope function, which gives you the polygon representation of this bounding box. But from there it is still not that straightforward to get the 4 bounding coordinates.

[caspervdw]

The GEOS C-API exposes Xmin, Xmax, Ymin, Ymax functions since version 3.7. That is probably what we need. I do wonder if performing the envelope and getting the values from the coordinate sequence would be more efficient.

[caspervdw]

As discussed in #69, we would also like a total_bounds function

[brendan-ward]

@caspervdw this appears resolved as of #69, #107

[jorisvandenbossche]

Indeed!