# Tag Archives: geometry

## Convert From GDS to LinearRing

Convert From GDS to LinearRing GDS is a common format for electronic circuit designs, MEMS and other technologies.  At the moment I’m working on a project to convert from gds to a format for electron beam lithography. Whilst it might be possible to work directly with the gds files themselves, it made much more sense… Read More »

## How to find the Centre of a Polygon in Python

Finding the centre of of a polygon can be useful for many geomtrical analysis and processing techniques. This quick guide shows you how to find the centre of a polygon in python. The Centroid The centre of a polygon is also known as its centroid. It the arithmetic mean position of all the points that… Read More »

## How to Merge Polygons in Python

I’ve been working with the Shapely python package in python. This is a short guide for how to merge polygons in python. This guide is based on “cascaded_union.py” in the shapely examples. Find out how to install shapely in python here. How to Merge Polygons in Python Download the script for this guide here. In… Read More »

## Trapezoidal Decomposition of Polygons in Python

Trapezoidal Decomposition Trapezoidal decomposition of polygons involves breaking a polygon into a series of smaller trapezoids. I’ve been working on a project – gds2ecp – to decompose lithography design files into compound shapes that can be written by electron beam lithography. I was sure that there would be an existing library to do the polygon… Read More »

## How to Find the Concave Hull in Python

How to Find the Concave Hull in Python The Python module Shapely has a built in function for determining the convex hull, but for determining the concave hull (or alpha shape), you have to do a bit more work. Thankfully a few people on the internet have already done much of the work in determining… Read More »