TypeError: '<' not supported between instances of 'Cell' and 'Cell'

[adnanobot]

Hi,

when I provide input like the following,
coordinates = [[[100, 0], [101, 0], [110, 10], [100, 1], [100, 0]]]

Then it's ok and I am getting the output, Centroid: [101.25, 1.25]

But if I just change the second coordinate,
coordinates = [[[100, 0], [105, 0], [110, 10], [100, 1], [100, 0]]]

then I get the following error:
Traceback (most recent call last): File "curve2poly.py", line 75, in <module> centroid = polylabel(x) File "C:\Users\mahmad\vision\lib\site-packages\polylabel\__init__.py", line 138, in polylabel _, __, cell = cell_queue.get() File "C:\Program Files\Python37\lib\queue.py", line 180, in get item = self._get() File "C:\Program Files\Python37\lib\queue.py", line 236, in _get return heappop(self.queue) TypeError: '<' not supported between instances of 'Cell' and 'Cell'

I am not getting what kind of input polylabel() takes? It should work with any shape and size of polygons, right?

Update: It is working fine in ubuntu but not in windows.

[Twista]

That is interesting. I just tried to run that code in python3.7 (as it seems your machine is using it) and everything works great.

I have made test case for it, but I have no idea where to look, as I have no access to windows computer.

Would you mind to take a closer look?

[adnanobot]

Yes, I have found the solution by modifying the Cell class in __init__.py.
I followed the suggestion from here: https://github.com/laurentluce/python-algorithms/issues/6.

So I have also modified the Cell class:

class Cell(object):
    def __init__(self, x, y, h, polygon):
        self.h = h
        self.y = y
        self.x = x
        self.d = _point_to_polygon_distance(x, y, polygon)
        self.max = self.d + self.h * sqrt(2)

    def __lt__(self, other):
        return self.max < other.max

Now it is working but I did not understand his explanation. Can you please explain the reason?

[Twista]

It seems that in some cases (where values are same) queue is trying to sort elements. and to perform sorting in needs to compare two elements which has higher/lower elements. Therefore it performs < operator on to the Cell class - which doesn't support it.

by declaring __lt__ you tell python how < (less-than) should behave.

Thanks a lot for checking it and providing a solution. I will add it to the code-base and create new package version soon :)

[Twista]

version 0.6 released. feel free to update :))

[adnanobot]

ok...got it! thanks for the explanation!