# R: Bivariate Clusplot of a Partitioning Object

clusplot.partition {cluster} | R Documentation

## Bivariate Clusplot of a Partitioning Object

### Description

Clusplot (Clustering Plot) method for an object of class `partition`.

### Usage

    ## S3 method for class 'partition':
    clusplot(x, main = NULL, dist = NULL, ...)

### Arguments

`x` | an object of class `"partition"`, e.g. created by the functions `pam`, `clara`, or `fanny`.
`main` | title for the plot; when `NULL` (by default), a title is constructed, using `x$call`.
`dist` | when `x` does not have a `diss` nor a `data` component, e.g., for `pam(dist(*), keep.diss=FALSE)`, `dist` must specify the dissimilarity for the clusplot.
`...` | all optional arguments available for the `clusplot.default` function (except for the `diss` one) may also be supplied to this function. Graphical parameters (see `par`) may also be supplied as arguments to this function.

### Details

This `clusplot.partition()` method relies on `clusplot.default`.

If the clustering algorithms `pam`, `fanny` and `clara` are applied to a data matrix of observations-by-variables then a clusplot of the resulting clustering can always be drawn. When the data matrix contains missing values and the clustering is performed with `pam` or `fanny`, the dissimilarity matrix will be given as input to `clusplot`. When the clustering algorithm `clara` was applied to a data matrix with NAs then clusplot will replace the missing values as described in `clusplot.default`, because a dissimilarity matrix is not available.

### Value

An invisible list with components

`Distances` | When option lines is 1 or 2 we optain a k by k matrix (k is the number of clusters). The element at row j and column s is the distance between ellipse j and ellipse s. If lines=0, then the value of this component is NA.

`Shading`

A vector of length k (where k is the number of clusters), containing the amount of shading per cluster. Let y be a vector where element i is the ratio between the number of objects in cluster i and the area of ellipse i. When the cluster i is a line segment, y[i] and the density of the cluster are set to NA. Let z be the sum of all the elements of y without the NAs. Then we put shading = y/z *37 + 3.

### See Also

`clusplot.default` for references; `partition.object`, `pam`, `pam.object`, `clara`, `clara.object`, `fanny`, `fanny.object`, `par`.

### Examples

    ## generate 25 objects, divided into 2 clusters.
    x <- rbind(cbind(rnorm(10,0,0.5), rnorm(10,0,0.5)),
               cbind(rnorm(15,5,0.5), rnorm(15,5,0.5)))
    clusplot(pam(x, 2))
    ## add noise, and try again :
    x4 <- cbind(x, rnorm(25), rnorm(25))
    clusplot(pam(x4, 2))

[Package cluster version 1.11.9 Index]