circular.sil {CircularSilhouette} | R Documentation |
Calculating Silhouette on Circular Data Clusters
Description
A fast linear-time algorithm to calculate silhouette information on circular data with cluster labels.
Usage
circular.sil(O, cluster, Circumference, method = c("linear", "quadratic"))
Arguments
O |
a numeric vector of circular data points |
cluster |
an integer vector of cluster labels for each point |
Circumference |
a numeric value giving the circumference of the circle |
method |
a character value to specify the algorithm to calculate
the silhouette information. The default value is |
Details
If method
takes the value of "linear"
(default), the
silhouette information on circular data is calculated by a fast
linear-time algorithm; if method
is "quadratic"
,
a quadratic-time algorithm is used instead to calculate silhouette
by definition. There is an overhead of sorting if the
input data are not sorted.
One important assumption is that a cluster cannot be contained in another cluster in the input cluster labels.
Value
The function returns a numeric value of the average silhouette information calculated on the input circular data clusters.
Examples
O <- c(-1.2, -2, -3, -2.5, 1, 0.8, 1.5, 1.2)
cluster <- c(1, 1, 1, 1, 2, 2, 2, 2)
circular.sil(O, cluster, 3)