@Override
public ExampleSet apply(ExampleSet exampleSet) throws OperatorException {
Attributes attributes = exampleSet.getAttributes();
Set<Attribute> attributeSubset = attributeSelector.getAttributeSubset(exampleSet, true);
Iterator<Attribute> r = attributes.allAttributes();
while (r.hasNext()) {
Attribute attribute = r.next();
if (!attributeSubset.contains(attribute)) r.remove();
}
return exampleSet;
}
private Attribute[] getMatchingAttributes(Attributes attributes, String regex)
throws OperatorException {
Pattern pattern = null;
try {
pattern = Pattern.compile(regex);
} catch (PatternSyntaxException e) {
throw new UserError(this, 206, regex, e.getMessage());
}
List<Attribute> attributeList = new LinkedList<Attribute>();
Iterator<Attribute> iterator = attributes.allAttributes();
while (iterator.hasNext()) {
Attribute attribute = iterator.next();
if (pattern.matcher(attribute.getName()).matches()) {
attributeList.add(attribute);
}
}
// building array of attributes for faster access.
Attribute[] attributesArray = new Attribute[attributeList.size()];
attributesArray = attributeList.toArray(attributesArray);
return attributesArray;
}