dice {diceR}

Diverse Clustering Ensemble

Description

Runs consensus clustering across subsamples, algorithms, and number of clusters (k).

Usage

dice(
  data,
  nk,
  p.item = 0.8,
  reps = 10,
  algorithms = NULL,
  k.method = NULL,
  nmf.method = c("brunet", "lee"),
  hc.method = "average",
  distance = "euclidean",
  cons.funs = c("kmodes", "majority", "CSPA", "LCE", "LCA"),
  sim.mat = c("cts", "srs", "asrs"),
  prep.data = c("none", "full", "sampled"),
  min.var = 1,
  seed = 1,
  seed.data = 1,
  trim = FALSE,
  reweigh = FALSE,
  n = 5,
  evaluate = TRUE,
  plot = FALSE,
  ref.cl = NULL,
  progress = TRUE
)

Arguments

data

data matrix with rows as samples and columns as variables

nk

number of clusters (k) requested; can specify a single integer or a range of integers to compute multiple k

p.item

proportion of items to be used in subsampling within an algorithm

reps

number of subsamples

algorithms

vector of clustering algorithms for performing consensus clustering. Must be any number of the following: "nmf", "hc", "diana", "km", "pam", "ap", "sc", "gmm", "block", "som", "cmeans", "hdbscan". A custom clustering algorithm can be used.

k.method

determines the method to choose k when no reference class is given. When ref.cl is not NULL, k is the number of distinct classes of ref.cl. Otherwise the input from k.method chooses k. The default is to use the PAC to choose the best k(s). Specifying an integer as a user-desired k will override the best k chosen by PAC. Finally, specifying "all" will produce consensus results for all k. The "all" method is implicitly performed when there is only one k used.

nmf.method

specify NMF-based algorithms to run. By default the "brunet" and "lee" algorithms are called. See NMF::nmf() for details.

hc.method

agglomeration method for hierarchical clustering. The the "average" method is used by default. Seestats::hclust() for details.

distance

a vector of distance functions. Defaults to "euclidean". Other options are given in stats::dist(). A custom distance function can be used.

cons.funs

consensus functions to use. Current options are "kmodes" (k-modes), "majority" (majority voting), "CSPA" (Cluster-based Similarity Partitioning Algorithm), "LCE" (linkage clustering ensemble), "LCA" (latent class analysis)

sim.mat

similarity matrix; choices are "cts", "srs", "asrs".

prep.data

Prepare the data on the "full" dataset, the "sampled" dataset, or "none" (default).

min.var

minimum variability measure threshold used to filter the feature space for only highly variable features. Only features with a minimum variability measure across all samples greater than min.var will be used. If type = "conventional", the standard deviation is the measure used, and if type = "robust", the MAD is the measure used.

seed

random seed for knn imputation reproducibility

seed.data

seed to use to ensure each algorithm operates on the same set of subsamples

trim

logical; if TRUE, algorithms that score low on internal indices will be trimmed out

reweigh

logical; if TRUE, after trimming out poor performing algorithms, each algorithm is reweighed depending on its internal indices.

n

an integer specifying the top n algorithms to keep after trimming off the poor performing ones using Rank Aggregation. If the total number of algorithms is less than n no trimming is done.

evaluate

logical; if TRUE (default), validity indices are returned. Internal validity indices are always computed. If ref.cl is not NULL, then external validity indices will also be computed.

plot

logical; if TRUE, graph_all is called and a summary evaluation heatmap of ranked algorithms vs. internal validity indices is plotted as well.

ref.cl

reference class

progress

logical; should a progress bar be displayed?

Details

There are three ways to handle the input data before clustering via argument prep.data. The default is to use the raw data as-is ("none"). Or, we can enact prepare_data() on the full dataset ("full"), or the bootstrap sampled datasets ("sampled").

Value

A list with the following elements

E

raw clustering ensemble object

Eknn

clustering ensemble object with knn imputation used on E

Ecomp

flattened ensemble object with remaining missing entries imputed by majority voting

clusters

final clustering assignment from the diverse clustering ensemble method

indices

if evaluate = TRUE, shows cluster evaluation indices; otherwise NULL

Author(s)

Aline Talhouk, Derek Chiu

Examples

library(dplyr)
data(hgsc)
dat <- hgsc[1:100, 1:50]
ref.cl <- strsplit(rownames(dat), "_") %>%
  purrr::map_chr(2) %>%
  factor() %>%
  as.integer()
dice.obj <- dice(dat, nk = 4, reps = 5, algorithms = "hc", cons.funs =
"kmodes", ref.cl = ref.cl, progress = FALSE)
str(dice.obj, max.level = 2)