![voronoi diagrams voronoi diagrams](https://miro.medium.com/max/5120/1*LHhHsQLYtCK1icoBsGdXCw.png)
![voronoi diagrams voronoi diagrams](https://www.jasondavies.com/maps/voronoi/airports/full.png)
This demonstrated very convincingly that contaminate water was indeed the cause of cholera. It turned out that almost all the deaths marked on the map lay inside the catchment area of the Broad Street pump and anecdotal evidence explained the few cases that did not.
![voronoi diagrams voronoi diagrams](https://i.imgur.com/pXwRA3D.jpg)
Points within this catchment area were closer to the Broad Street pump than any other pump - only that, unlike in our example above, Snow didn't use the direct distance a crow would fly, but the walking distance along streets and alleys. The easiest to understand is a simple brute force approach: For each pixel we care about, simply calculate the. He then also identified the "catchment area" of a particular water pump at 40 Broad Street (now Broadwick Street). There are many ways to generate Voronoi diagrams. He was able to convince others of his theory by first marking the number of deaths at each address on a map of Soho. It was thought at the time that the disease was caused by "bad air", but physician John Snow had another idea: he thought that cholera came from contaminated water supplies, which in those days came from pumps positioned throughout the city. In the 1850s a cholera outbreak was decimating Soho in London, killing 10% of the population and wiping out entire families in days. The curve marks points at equal distance from the Broad Street pump and another pump.īut we chose the medical analogy for a reason. Each bar represents a death at an address.