intersection of linestring and polygen are wrong in some situations

# # -*- coding: utf-8 -*-
from pygeos import set_operations
from pygeos import linestrings
from pygeos import polygons
import numpy as np

if __name__ == '__main__':
    area = np.array([[1240, 8], [70, 30], [70, 704], [1250, 689], [1240, 8]])
    area = polygons(area)

    edge1 = linestrings(np.array([[600, 117.1], [635, 117.1]]))
    intersection = set_operations.intersection(area, edge1)
    print(area, edge1, intersection)

    edge2 = linestrings(np.array([[600, 116], [635, 117.1]]))
    intersection = set_operations.intersection(area, edge2)
    print(area, edge2, intersection)

it works correctly in version 0.8.

[jorisvandenbossche]

pygeos 0.10 was just released yesterday, and the wheels are built with GEOS 3.9.1. So you should be able to update to that.

[hehaha]

I’m sorry about my expression, I’m not mean to be rude. I do don’t know this capital rule. Sorry about that.

As this problem, in 0.9 the output is:

POLYGON ((1.24e+03 8, 70 30, 70 704, 1.25e+03 689, 1.24e+03 8)) LINESTRING (600 117, 635 117) LINESTRING EMPTY
POLYGON ((1.24e+03 8, 70 30, 70 704, 1.25e+03 689, 1.24e+03 8)) LINESTRING (600 116, 635 117) LINESTRING (600 116, 635 117)

In 0.8, the output is:

POLYGON ((1.24e+03 8, 70 30, 70 704, 1.25e+03 689, 1.24e+03 8)) LINESTRING (600 117, 635 117) LINESTRING (600 117, 635 117)
POLYGON ((1.24e+03 8, 70 30, 70 704, 1.25e+03 689, 1.24e+03 8)) LINESTRING (600 116, 635 117) LINESTRING (600 116, 635 117)

And the weird thing is that intersection is wrong when I input a linestring with same y. Like (600 117, 635 117), same y as 117.