ParallelSliceFitter

[forcar]

Three suggestions:

1. Replace ArrayList with synchronized list (avoiding thread collisions):
   // ArrayList fitResults = new ArrayList();
   List fitResults = Collections.synchronizedList(new ArrayList());

2. Remove progress code with Thread.sleep which was evidently intended to minimize thread collisions. This speeds up ParallelSliceFitter by at least x10.

3. fitResults are filled from slice threads and therefore not in ascending bin sequence. Resort:
   fitResults.sort(Comparator.comparing(FitResults::getPoint));