CODEWITHSUNDEEP
python
user8400129
user8400129

Reputation: 213

How to judge if a polygon is inside another polygon in Python?

I need to define a Python function which can dectect if a convex polygon (polygon a) is inside another polygon(polygon b).

The vertex of each polygon are given.

(only use basic lib as well as numpy)

It’s easy for a human to make a judgement with their eyes. But I have no idea how to describe the method in Python. I have tried to check some source code of lib (like shapely) but can't understand how it works. '''

def isinside(polya, polyb):
     #Polya: [(x1,y1), (x2,y2), (x3,y3),...]
     #Polyb: [(x1,y1), (x2,y2), (x3,y3),...]
    #if polya inside polyb
     return True
     # else 
     return False

''' Could someone please give some advice or show some codes? Thanks!

Upvotes: 11

Views: 10799

Answers (1)

Julio Cezar Silva
Julio Cezar Silva

Reputation: 2456

You could use the shapely lib for that. It'd go like

from shapely.geometry import Polygon

polya = Polygon([(0, 0), (0, 1), (1, 1), (1, 0)]) 
polyb = Polygon([(0.5, 0.5), (0.5, 0.8), (0.8, 0.8), (0.8, 0.5)]) 

polya.contains(polyb)
# True

This module has got a lot more on most geometry related operations, so refer to their User Manual for further examples and thorough explanations.

Upvotes: 19

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