static double[] incremental(final double[] values) {
		final DoubleAdder adder = new DoubleAdder(values[0]);
		for (int i = 1; i < values.length; ++i) {
			values[i] = adder.add(values[i]).doubleValue();
		}
		return values;
	}
In-place summation of the probability array.
jenetics/src/main/java/io/jenetics/ProbabilitySelector.java