@Override
public FunctionValues getValues(Map context, AtomicReaderContext readerContext) throws IOException {
final FieldCache.Doubles arr = cache.getDoubles(readerContext.reader(), field, parser, true);
final Bits valid = cache.getDocsWithField(readerContext.reader(), field);
return new DoubleDocValues(this) {
@Override
public double doubleVal(int doc) {
return arr.get(doc);
}