# banditpam

We provide an R interface to the high-performance implementation of banditpam, a $$k$$-medoids clustering algorithm.

If you use this software, please cite:

Mo Tiwari, Martin Jinye Zhang, James Mayclin, Sebastian Thrun, Chris Piech, Ilan Shomorony. “banditpam: Almost Linear Time k-medoids Clustering via Multi-Armed Bandits” Advances in Neural Information Processing Systems (NeurIPS) 2020.

Here’s a BibTeX entry:

@inproceedings{banditpam,
title={banditpam: Almost Linear Time k-medoids Clustering via Multi-Armed Bandits},
author={Tiwari, Mo and Zhang, Martin J and Mayclin, James and Thrun, Sebastian and Piech, Chris and Shomorony, Ilan},
booktitle={Advances in Neural Information Processing Systems},
pages={368--374},
year={2020}
}

## Installation

banditpam can be installed from CRAN like any other package.

## Example

This is a basic example which shows you how to solve a common problem:

library(banditpam)
## Generate data from a Gaussian Mixture Model with the given means:
set.seed(10)
n_per_cluster <- 40
means <- list(c(0, 0), c(-5, 5), c(5, 5))
X <- do.call(rbind, lapply(means, MASS::mvrnorm, n = n_per_cluster, Sigma = diag(2)))
## Create KMediods object
obj <- KMedoids$new(k = 3) ## Fit data obj$fit(data = X, loss = "l2")
## Retrieve medoid indices
meds <- obj$get_medoids_final() ## Plot the results plot(X[, 1], X[, 2]) points(X[meds, 1], X[meds, 2], col = "red", pch = 19) ## ## One can query some statistics too; see help("KMedoids") ## obj$get_statistic("dist_computations")
obj$get_statistic("dist_computations_and_misc") obj$get_statistic("cache_misses")