Find all coordinates within a circle in geographic data in python

Question

I\'ve got millions of geographic points. For each one of these, I want to find all \"neighboring points,\" i.e., all other points within some radius, say a few hundred meters.<

Answer 1

Tipped off by Eamon, I've come up with a simple solution using btrees implemented in SciPy.

from scipy.spatial import cKDTree
from scipy import inf

max_distance = 0.0001 # Assuming lats and longs are in decimal degrees, this corresponds to 11.1 meters
points = [(lat1, long1), (lat2, long2) ... ]
tree = cKDTree(points)

point_neighbors_list = [] # Put the neighbors of each point here

for point in points:
    distances, indices = tree.query(point, len(points), p=2, distance_upper_bound=max_distance)
    point_neighbors = []
    for index, distance in zip(indices, distances):
        if distance == inf:
            break
        point_neighbors.append(points[index])
    point_neighbors_list.append(point_neighbors)