/**
* @param record
* @return the group which has nearest center to the <tt>record</tt>
*/
private EvaluationRecordGroup getNearestGroup(EvaluationRecord record) {
EvaluationRecordGroup minGroup = null;
double minGroupDistance = 0;
for (EvaluationRecordGroup group : groupClusterCenter.keySet()) {
double testDistance = groupClusterCenter.get(group).getLength(record.getConsideringValues());
if (minGroup == null || testDistance < minGroupDistance) {
minGroup = group;
minGroupDistance = testDistance;
}
}
return minGroup;
}
/**
* calculates center of <tt>records</tt> using averaging algorithm.
*
* @param records
* @return
*/
private Coordination calculateCenter(Collection<EvaluationRecord> records) {
if (records.size() > 0) {
double[] centerCoord = new double[coordinateSize];
for (EvaluationRecord record : records) {
List<Double> cFactors = record.getConsideringValues();
for (int i = 0; i < centerCoord.length; i++) {
centerCoord[i] += cFactors.get(i);
}
}
for (int i = 0; i < centerCoord.length; i++) {
centerCoord[i] /= records.size();
}
return new Coordination(centerCoord);
}
double[] returnVal = new double[coordinateSize];
Arrays.fill(returnVal, 0d);
return new Coordination(returnVal);
}