spherical-geometry

1.4.0 verified Fri May 01 auth: no python

Python tools for spherical geometry, providing vectorized operations on the sphere using NumPy. Current version 1.4.0, released approximately monthly.

pip install spherical-geometry

Common errors

error AttributeError: module 'spherical_geometry' has no attribute 'Arc' ↓

cause Using an older version (<1.4.0) where Arc was not exported at package level, or importing incorrectly.

fix

Upgrade to version 1.4.0+ (pip install --upgrade spherical-geometry) and use from spherical_geometry import Arc.

error ValueError: All points must be in radians ↓

cause Passing coordinates in degrees instead of radians.

fix

Convert lon, lat to radians using math.radians() or numpy.radians() before passing to spherical_geometry functions.

Warnings

breaking In version 1.4.0, the import paths for Arc and GreatCircle changed. Previously they were in submodules; now they are exported at the top-level package. Code using old imports will fail. ↓

fix Use `from spherical_geometry import Arc, GreatCircle` instead of `from spherical_geometry.polygon import Arc` or `from spherical_geometry.great_circle import GreatCircle`.

gotcha All angular coordinates (longitude, latitude) must be in radians, not degrees. The library does not perform conversion, and passing degrees will give incorrect results. ↓

fix Convert degrees to radians using `math.radians()` or `numpy.radians()` before passing to functions.

deprecated The `spherical_geometry.polygon` module is deprecated as of 1.4.0. Its contents have been moved to the top-level package. ↓

fix Use top-level imports as shown in the quickstart.

Imports

Arc
wrong
```
from spherical_geometry.polygon import Arc
```
correct
```
from spherical_geometry import Arc
```
Arc is available at package level since v1.4.0; previous location was deprecated.

GreatCircle

wrong

from spherical_geometry.great_circle import GreatCircle

correct

from spherical_geometry import GreatCircle

GreatCircle is exported at the package level; direct module import may break.

Quickstart

Basic usage of Arc and GreatCircle for spherical geometry calculations.

from spherical_geometry import Arc, GreatCircle

# Define two points on the sphere (longitude, latitude in radians)
point_a = (0.0, 0.0)
point_b = (1.0, 0.5)

# Create a great circle arc
arc = Arc(point_a, point_b)
print(f"Arc length: {arc.length()}")

# Compute intersection of two great circles
gc1 = GreatCircle(point_a, point_b)
gc2 = GreatCircle((0.5, 0.2), (1.2, 0.8))
intersections = gc1.intersections(gc2)
print(f"Intersection points: {intersections}")