KmeansParam-class {bluster} | R Documentation

## K-means clustering

### Description

Run the base `kmeans` function with the specified number of centers within `clusterRows`.

### Usage

    KmeansParam(centers, iter.max = NULL, nstart = NULL, algorithm = NULL)

    ## S4 method for signature 'ANY,KmeansParam'
    clusterRows(x, BLUSPARAM, full = FALSE)

### Arguments

`centers` | An integer scalar specifying the number of centers. Alternatively, a function that takes the number of observations and returns the number of centers.
`iter.max, nstart, algorithm` | Further arguments to pass to `kmeans`. Set to the `kmeans` defaults if not supplied.
`x` | A numeric matrix-like object where rows represent observations and columns represent variables.
`BLUSPARAM` | A KmeansParam object.
`full` | Logical scalar indicating whether the full k-means statistics should be returned.

### Details

This class usually requires the user to specify the number of clusters beforehand. However, we can also allow the number of clusters to vary as a function of the number of observations. The latter is occasionally useful, e.g., to allow the clustering to automatically become more granular for large datasets.

To modify an existing KmeansParam object `x`, users can simply call `x[[i]]` or `x[[i]] <- value` where `i` is any argument used in the constructor.

### Value

The `KmeansParam` constructor will return a KmeansParam object with the specified parameters.

The `clusterRows` method will return a factor of length equal to `nrow(x)` containing the cluster assignments. If `full=TRUE`, a list is returned with `clusters` (the factor, as above) and `objects` (a list containing `kmeans`, the direct output of `kmeans`).

### Author(s)

Aaron Lun

### See Also

`kmeans`, which actually does all the heavy lifting.

MbkmeansParam, for a faster but more approximate version of the k-means algorithm.

### Examples

    clusterRows(iris[,1:4], KmeansParam(centers=4))
    clusterRows(iris[,1:4], KmeansParam(centers=4, algorithm="Lloyd"))
    clusterRows(iris[,1:4], KmeansParam(centers=sqrt))

[Package bluster version 1.2.1 Index]