dbscan - Density Based Clustering of Applications with Noise (DBSCAN) and Related Algorithms - R package

This R package provides a fast C++ reimplementation of several density-based algorithms of the DBSCAN family for spatial data. Includes the DBSCAN (density-based spatial clustering of applications with noise) and OPTICS/OPTICSXi (ordering points to identify the clustering structure) clustering algorithms and the LOF (local outlier factor) algorithm. The implementations uses the kd-tree data structure (from library ANN) for faster k-nearest neighbor search. An R interface to fast kNN and fixed-radius NN search is also provided.

This implementation is typically faster than the native R implementation in package fpc, or the implementations in WEKA, ELKI and Python's scikit-learn.

Installation

Stable CRAN version: install from within R with

install.packages("dbscan")

Current development version: Download package from AppVeyor or install from GitHub (needs devtools).

install_git("mhahsler/dbscan")

Usage

Load the package and use the numeric variables in the iris dataset

library("dbscan")

data("iris")
x <- as.matrix(iris[, 1:4])

Run DBSCAN

db <- dbscan(x, eps = .4, minPts = 4)
db

DBSCAN clustering for 150 objects.
Parameters: eps = 0.4, minPts = 4
The clustering contains 4 cluster(s) and 25 noise points.

 0  1  2  3  4 
25 47 38 36  4 

Available fields: cluster, eps, minPts

Visualize results (noise is shown in black)

pairs(x, col = db$cluster + 1L)

Calculate LOF (local outlier factor) and visualize (larger bubbles in the visualization have a larger LOF)

lof <- lof(x, k = 4)
pairs(x, cex = lof)

Run OPTICS

opt <- optics(x, eps = 1, minPts = 4)
opt

OPTICS clustering for 150 objects.
Parameters: minPts = 4, eps = 1, eps_cl = NA, xi = NA
Available fields: order, reachdist, coredist, predecessor, minPts, eps, eps_cl, xi

Extract DBSCAN-like clustering from OPTICS and create a reachability plot (extracted DBSCAN clusters at eps_cl=.4 are colored)

opt <- extractDBSCAN(opt, eps_cl = .4)
plot(opt)

Extract a hierarchical clustering using the Xi method (captures clusters of varying density)

opt <- extractXi(opt, xi = .05)
opt
plot(opt)

License

The dbscan package is licensed under the GNU General Public License (GPL) Version 3. The OPTICSXi R implementation was directly ported from the ELKI framework's Java implementation (GNU AGPLv3), with explicit permission granted by the original author, Erich Schubert.

Further Information

• Development version of dbscan on github.
• List of changes from NEWS.md
• dbscan reference manual

Maintainer: Michael Hahsler