We added this for the 25 May demo. We’re unlikely to need it again.
We’re also unlikely to need this library again, so this commit removes
the source and the code that creates it.
Brings in https://github.com/alphagov/notifications-utils/pull/889/files
At the moment, we are not doing any transformation of features before
applying geometric algorithms to them. This is, in effect, assuming that
the earth is flat.
This new version of utils implements the transformation of our polygons
to a Cartesian plane. In other words, it converts them from being
defined in spherical degrees to metres.
For the admin app this means we need to convert places where the code
expects things to be measured in degrees to work in metres instead.
The Python rtree library we are using to build RTrees has a dependency
on the C package libspatialindex. This package is not installed on PaaS,
so it’s hard for us to use it.
This commit changes the code to use a library called rtreelib instead.
rtreelib doesn’t have a built in way to serialise the index it builds,
so I’ve had to implement that using pickle.
