public BoxPlot(Var x, Var factor, GOpt... opts) {
Map<String, List<Double>> map =
x.stream().collect(groupingBy(s -> factor.label(s.row()), mapping(VSpot::value, toList())));
names = factor.streamLevels().filter(map::containsKey).toArray(String[]::new);
vars = Arrays.stream(names).map(map::get).map(Numeric::copy).toArray(Var[]::new);
this.options.apply(opts);
initialize();
}
