OPTICS: Core Distance Calculation

[uarga]

OPTICS: Core Distance Calculation

[uhho]

@FredericMarkert Definitely agreed. Thanks a lot!
I've changed just one thing; when looking for neighbours there is no need to include the core point itself. So I think we can use _regionQuery() function here.

Next time, please feel free to send a pull request!

[uarga]

I'm glad to be helpful.

About including the core point: I wasn't sure about that, as the original paper does not elaborate on whether it's a closed or open neighborhood...

[uarga]

Well, I'm confused. The following regards DBSCAN, but should be analogue to OPTICS:

In the DBSCAN wikipedia article, it is stated that core points are included:

regionQuery(P, eps): return all points within P's eps-neighborhood (including P)

In the article talk section, I asked whether this is a mistake:

The authors do not elaborate on whether it's a closed or open neighborhood. The last sentence of the article about neighborhoods [...] would suggest to exclude P unless it is explicitly stated otherwise.

Here's a reply:

In a database context, such as when using an R*-tree as recommended by the authors, the query would include the query point. It is part of the database, too

Can you clarify?

[uhho]

I've just released new version (1.2.0). From now core points are included in region queries, both in DBSCAN and OPTICS.