# Cluster quality statistics

### Description

Compute several quality statistics of a given clustering solution.

### Usage

1 | ```
wcClusterQuality(diss, clustering, weights = NULL)
``` |

### Arguments

`diss` |
A dissimilarity matrix or a dist object (see |

`clustering` |
Factor. A vector of clustering membership. |

`weights` |
optional numerical vector containing weights. |

### Details

Compute several quality statistics of a given clustering solution. See value for details.

### Value

A list with two elements `stats`

and `ASW`

:

`stats`

with the following statistics:

- PBC
Point Biserial Correlation. Correlation between the given distance matrice and a distance which equal to zero for individuals in the same cluster and one otherwise.

- HG
Hubert's Gamma. Same as previous but using Kendall's Gamma coefficient.

- HGSD
Hubert's Gamma (Somers'D). Same as previous but using Somers' D coefficient.

- ASW
Average Silhouette width (observation).

- ASWw
Average Silhouette width (weighted).

- CH
Calinski-Harabasz index (Pseudo F statistics computed from distances).

- R2
Share of the discrepancy explained by the clustering solution.

- CHsq
Calinski-Harabasz index (Pseudo F statistics computed from

*squared*distances).- R2sq
Share of the discrepancy explained by the clustering solution (computed using

*squared*distances).- HC
Hubert's C coefficient.

`ASW`

:The Average Silhouette Width of each cluster, one column for each ASW measure.

### Examples

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | ```
data(mvad)
## Aggregating state sequence
aggMvad <- wcAggregateCases(mvad[, 17:86], weights=mvad$weight)
## Creating state sequence object
mvad.seq <- seqdef(mvad[aggMvad$aggIndex, 17:86], weights=aggMvad$aggWeights)
## Computing Hamming distance between sequence
diss <- seqdist(mvad.seq, method="HAM")
## KMedoids using PAMonce method (clustering only)
clust5 <- wcKMedoids(diss, k=5, weights=aggMvad$aggWeights, cluster.only=TRUE)
## Compute the silhouette of each observation
qual <- wcClusterQuality(diss, clust5, weights=aggMvad$aggWeights)
print(qual)
``` |