This is a simple method that, given a list of 2d points that constitutes the border of a shape, finds all the segments that start from the points on the border, pass through the mean of the points, and end on the border again. Then it finds the longest segment among them.

First you need to have (or create) an environment using the requirements.txt file (this will allow you to use the extractor_class.py, however to run the example.ipynb you are going to need the plotly library). To use the code, simply clone the repo and use the code contained in the extractor_class.py file, as shown in example.ipynb.

The code is really simple, don't get discouraged by the length of the code on the notebook, most of it belongs to the plotting part!

An example of the figure used in the example notebook is:

Then it is possible to extract all the edges that make the figure:

And finally compute all the segments that start from the points that define the border and arrive on the other side, finding the longest one: