would it be possible to have the CRS bounds in its original unit ?

[12rambau]

Let's assume I want to get the bounds of the projection 'EPSG:3857' in meters (unit of the 3857 projection)

In the current implementation of pyproj and with my little knowledge I would do the following :

from pyproj import CRS, Transformer

in_crs = CRS.from_epsg(4326)
out_crs = CRS.from_epsg(3857)
x_min, y_min, x_max, y_max = out_crs.area_of_use.bounds

proj = Transformer.from_crs(4326, 3857, always_xy=True)
bl = proj.transform(x_min, y_min)
tr = proj.transform(x_max, y_max)

that's a lot of steps just to extract the bounds in the original proj unit.
Would it be possible to add a method to retrieve the projection in its original unit ?

I would be happy to PR this very code in PR if you agree with this way of computing it.

maybe I'm foolish and there is already a way to retrieve the bounds...

[snowman2]

To transform the boundary properly, would likely need a method similar to:
https://rasterio.readthedocs.io/en/latest/api/rasterio.warp.html#rasterio.warp.transform_bounds

[snowman2]

PROJ does something similar:
https://github.com/OSGeo/PROJ/blob/5fb47f125c25751bd1b1018849de9e7ee69107f4/src/4D_api.cpp#L974-L1043

[snowman2]

How to get projected bounds with #810:

from pyproj import CRS, Transformer

crs = CRS("EPSG:3857")
transformer = Transformer.from_crs(crs.geodetic_crs, crs, always_xy=True)
transformer.transform_bounds(*crs.area_of_use.bounds)

[12rambau]

awesome ! thanks a lot

I have edited my answer on GIS.Stackexchange: https://gis.stackexchange.com/questions/390517/getting-projected-bounds-information-in-pyproj/392407#392407

let me know when it will be released !

[snowman2]

Release is coming soon. Hopefully by the end of the week 🤞