uxarray.grid.intersections.gca_const_lat_intersection

uxarray.grid.intersections.gca_const_lat_intersection(gca_cart, const_z)

Return the intersection points of a great-circle arc and a latitude.

Dispatcher / convenience API. Runs the numerical kernel, validity masks, endpoint snapping, and packaging into UXarray’s NaN-filled (2,3) format. All UXarray-specific branching lives here so the numerical core stays uniform. See also: _try_gca_const_lat_intersection.

Parameters:

• gca_cart (iterable of 2 length-3 iterables) – Great-circle arc as two Cartesian endpoints. (If numpy array, has shape (2,3). If tuple, contains two length-3 tuples.)

• const_z (float) – Constant-latitude plane, given as the Cartesian z value sin(lat).

Returns:

intersections – The (x,y,z) coordinates of the intersections, filling with NaNs as needed. E.g. if there is one intersection, returns ((x1,y1,z1),(nan,nan,nan)).

Return type:

tuple of 2 length-3 tuples

References

Chen, H., Ullrich, P. A., Panetta, J., Marsico, D., Hanke, M., Jain, R., Zhang, C., and Jacob, R. L. (2026). Accurate and robust geometric algorithms for regridding on the sphere. Geoscientific Model Development, 19(14), 6545-6570. https://doi.org/10.5194/gmd-19-6545-2026

Chen, H., Ullrich, P. A., and Panetta, J. (2026). Fast and accurate intersections on a sphere. SIAM Journal on Scientific Computing, 48(2), B208-B232. https://doi.org/10.1137/25M1737614