Custom Layers

Now that we have covered the basics of visualizing geospatial data with built-in layers and methods to change the tile provider, we will now focus on defining our custom layers. Custom layers allow you to create more complex data visualizations. They also help with adding more interactivity and animation to them. Creating a custom layer starts by defining a new class that extends the BaseLayer class that's provided by geoplotlib. Besides the __init__ method, which initializes the class level variables, we also have to, at the very least, extend the draw method of the BaseLayer class already provided.

Depending on the nature of your visualization, you might also want to implement the invalidate method, which takes care of map projection changes such as zooming into your visualization. Both the draw and invalidate methods receive a Projection object that takes care of the latitude and longitude mapping on our two-dimensional viewport. These mapped points can be...