OPTICS should support sparse matrices and precomputed distances

[jnothman]

OPTICS relies on the nearest neighbor graph, and should be possible to perform with precomputed distances (maybe it does already, but I don't think it's tested), and with sparse feature spaces. It should perhaps also be possible to perform with sparse precomputed neighborhoods (e.g. as returned from radius_neighbors_graph(radius=max_bound)) but I've not double checked this.

[adrinjalali]

I tried and it doesn't support precomputed as it is. But it shouldn't be hard to fix.

[sophiastr]

Hello, i want to deal with this issue.
Do you still need help?
I am beginner, is that a problem?
I will work really hard in order to make my first contribution.