ca.pfv.spmf.algorithms.clustering.kmeans

Class AlgoKMeans

java.lang.Object

ca.pfv.spmf.algorithms.clustering.kmeans.AlgoKMeans

public class AlgoKMeans
extends java.lang.Object

An implementation of the K-means algorithm (J. MacQueen, 1967).

The K-means algorithm steps are (text from Wikipedia) : 1) Choose the number of clusters, k. * 2) Randomly generate k clusters and determine the cluster centers, or directly generate k random points as cluster centers. 3) Assign each point to the nearest cluster center. 4) Recompute the new cluster centers. 5) Repeat the two previous steps until some convergence criterion is met (usually that the assignment hasn't changed).

Constructor Summary

Constructors

Constructor and Description
AlgoKMeans() Default constructor

Method Summary

Modifier and Type	Method and Description
void	printStatistics() Print statistics of the latest execution to System.out.
java.util.List<Cluster>	runAlgorithm(java.lang.String inputFile, int k) Run the K-Means algorithm
void	saveToFile(java.lang.String output) Save the clusters to an output file

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AlgoKMeans

public AlgoKMeans()

Default constructor

Method Detail

runAlgorithm

public java.util.List<Cluster> runAlgorithm(java.lang.String inputFile,
                                            int k)
                                     throws java.lang.NumberFormatException,
                                            java.io.IOException

Run the K-Means algorithm

Parameters:

inputFile - an input file path containing a list of vectors of double values

k - the parameter k

Returns:

a list of clusters (some of them may be empty)

Throws:

java.io.IOException - exception if an error while writing the file occurs

java.lang.NumberFormatException

printStatistics

public void printStatistics()

Print statistics of the latest execution to System.out.

saveToFile

public void saveToFile(java.lang.String output)
                throws java.io.IOException

Save the clusters to an output file

Parameters:

output - the output file path

Throws:

java.io.IOException - exception if there is some writing error.