opt_kmedoids: Find optimal weights for Gower's metric and return the...

Description Usage Arguments Details Value Note Author(s) References See Also Examples

Description

This function is a wrapper function for find_kmedoids_weights that returns both the kmedoids clustering and the result from find_kmedoids_weights.

Usage

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opt_kmedoids(data, k, start_values = rep(1 / ncol(data), ncol(data) - 1),
                        n_iterate = 10,
                        bounds=c(1 / (3 * ncol(data)),
                        1 - (ncol(data) - 1) / (3 * ncol(data))))
                        

Arguments

data

the data that needs to be clustered, provided as a dataframe or (numeric) matrix. It is assumed that rows correspond to instances and columns correspond to features.

start_values

a vector containing the initial values of the weights. Defaults to 1/ncol(data) for all variables. They must not be negative. Furthermore, 1 - sum(start_values) >= bounds[1] must hold. Due to the way the algorithm is programmed, you only have to supply values for the first ncol(data) - 1 variables!

k

the number of clusters, the K in K-medoids.

n_iterate

the maximum number of iterations used by the quasi-newton method optim. Defaults to 10.

bounds

a vector of size 2 containing the lower and upper bound in position 1 and 2 respectively. The lower bound must not be lower than 0 and not higher than 1/ncol(data). The upper bound will be set to the minimum of its current value and 1-(ncol(data)-1)*bounds[1]. For more information, see details.

Details

See find_kmedoids_weights for more details.

Value

This function returns a list of two named lists:

clustering

the kmedoids clustering. See pam for more information.

opt_result

the results of the optimisation algorithm. See find_kmedoids_weights for more information.

Note

This package requires the cluster package.

Author(s)

Jeroen van den Hoven

References

Clustering with optimised weights for Gower's metric: Using hierarchical clustering and Quasi-Newton methods to maximise the cophenetic correlation coefficient, Jeroen van den Hoven.

See Also

find_kmedoids_weights

Examples

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## Basic example
data(mtcars)
find_kmedoids_weights(mtcars, k = 3)

## Using custom bounds
find_kmedoids_weights(mtcars, k = 3, bounds = c(0.05, 0.2))

Jeroentjeh/opthierarch documentation built on May 26, 2019, 7:28 a.m.