@Override
public void processDocument(Document doc) {
doc.addFeatureSet(FEATURE_SET, usedForClassification);
clusters.forEach(
(i, c) -> {
DoubleStream stream =
c.stream()
.mapToDouble(
(fn) -> doc.getFeature(fn) == null ? 0 : doc.getFeature(fn).doubleValue());
Double v = 0.0;
if (isMaxCombiner) {
v = stream.max().orElse(0);
} else { // if isSumCombiner
v = stream.sum();
}
if (v > 0) {
doc.getFeatureSet(FEATURE_SET).add(i.toString(), v);
}
});
}
public static void main(String[] args) {
// Page 45
// ========
IntStream.iterate(1, i -> i * 2).limit(10).forEachOrdered(System.out::println);
IntStream.range(1, 6).forEach(System.out::print); // prints 123456
// Page 46
// ========
List<Integer> intList = Arrays.asList(1, 2, 3);
OptionalDouble maxDistance =
intList.stream().map(i -> new Point(i % 3, i / 3)).mapToDouble(p -> p.distance(0, 0)).max();
DoubleStream ds =
intList.stream().map(i -> new Point(i % 3, i / 3)).mapToDouble(p -> p.distance(0, 0));
OptionalDouble maxDistance1 = ds.max();
// Page 48
// ========
Optional<Integer> max =
Arrays.asList(1, 2, 3, 4, 5).stream().map(i -> i + 1).max(Integer::compareTo);
// Page 49
// ========
OptionalInt max1 = IntStream.rangeClosed(1, 5).map(i -> i + 1).max();
DoubleStream ds1 = IntStream.rangeClosed(1, 10).asDoubleStream();
Stream<Integer> is = IntStream.rangeClosed(1, 10).boxed();
Stream<Integer> integerStream = Stream.of(1, 2);
IntStream is1 = integerStream.mapToInt(Integer::intValue);
}