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largeVis (version 0.2.1.1)

lv_optics: lv_optics

Description

Experimental implementation of the OPTICS algorithm.

Usage

lv_optics(edges, neighbors, eps = Inf, minPts = nrow(neighbors), eps_cl, xi,
  useQueue = TRUE, verbose = getOption("verbose", TRUE))

Arguments

edges

A weighted graph of the type produced by buildEdgeMatrix. Alternatively, a largeVis object, in which case edges and neighbors will be taken from the edges and knns parameters, respectively.

neighbors

An adjacency matrix of the type produced by randomProjectionTreeSearch

eps

See optics.

minPts

See optics.

eps_cl

See optics.

xi

See optics.

useQueue

Whether to process points in order of core distance. (See note.)

verbose

Vebosity level.

Value

An optics object.

Details

This is an implementation of the OPTICS algorithm that attempts to leverage the largeVis nearest-neighbor search.

This implementation does not use the OPTICS neighbor-search strategy, in favor of using the pre-calculated neighbor matrix produced incidentally by largeVis. It is therefore a variant of OPTICS rather than an implementation of the original, and the results vary slightly from those obtained by the implementations in ELKI and the dbscan package.

References

Mihael Ankerst, Markus M. Breunig, Hans-Peter Kriegel, Jorg Sander (1999). OPTICS: Ordering Points To Identify the Clustering Structure. ACM SIGMOD international conference on Management of data. ACM Press. pp. 49-60.