hcc_parallel {chickn} R Documentation

hcc_parallel

Description

Compressed Hierarchical Clustering.

Usage

hcc_parallel(
Data,
W,
K,
maxLevel,
ncores = 2,
DIR_output = tempfile(),
hybrid = FALSE,
verbose = FALSE,
...
)


Arguments

 Data A Filebacked Big Matrix n x N. Data signals are stored in the matrix columns. W A frequency matrix m x n with frequency vectros in rows. K Number of clusters at each call of the clustering algorithm. maxLevel Maximum number of hierarchical levels. ncores Number of cores. By default 4. DIR_output An output directory. hybrid logical parameter. If TRUE K decreases progressively over hierarchical levels as \lceil \frac{K}{level} \rceil. Default is FALSE. verbose logical that indicates whether dysplay the processing steps. ... Additional arguments passed on to COMPR.

Details

This function provides a divisive hierarchical implementation of COMPR. Parallel computations are performed using 'FORK' clusters (Linux-like platform) or 'PSOCK' clusters (Windows platform) using the parallel package. This function generates in the DIR_output directory the following files:

• 'Cluster_assign_out.bk' is a Filebacked Big Matrix N x maxLevel+1, which stores the cluster assignment at each hierarchical level.

• 'Centroids_out.bk' is a Filebacked Big Matrix with the resulting cluster centroids in columns.

Value

The cluster assignment as a list of clusters with corresponding data vector indeces.

References

Keriven N, Tremblay N, Traonmilin Y, Gribonval R (2017). “Compressive K-means.” In 2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP), 6369–6373. IEEE.

COMPR

Examples


data("UPS2")
N = ncol(UPS2)
n= nrow(UPS2)
X_FBM = bigstatsr::FBM(init = UPS2, ncol=N, nrow = n)$save() K_W1 = Nystrom_kernel(Data = X_FBM, c = 14, l = 7, s = 5, max_neighbors = 3, ncores = 1, kernel = 'Gaussian')$K_W1
W = GenerateFrequencies(Data = K_W1, m = 20, N0 = ncol(X_FBM))\$W
C = hcc_parallel(Data = K_W1, W = W, K = 2, maxLevel = 4,
DIR_output = tempfile(), ncores = 2)



[Package chickn version 1.2.3 Index]