This package does histogram binning on a unit sphere, i.e. binning of unit vectors. It also provides some plotting utilities.
Binning a single vector takes on the order of 25ns for 10_000 bins and 35ns for 1_000_000 bins on my machine.
Here's an example plot. The left side shows a histogram of 1e6 random unit vectors, sampled correctly. The right side shows normalize(2rand(3) .- 1.0), also one million samples.
