- All Superinterfaces:
- All Known Implementing Classes:
- CycleBasedPointSet.CycleBasedPointSetIterator, CycleBasedPointSetBase2.CycleBasedPointSetBase2Iterator
public interface PointSetIteratorextends RandomStreamObjects of classes that implement this interface are iterators that permit one to enumerate (or observe) the successive points of a point set and the successive coordinates of these points. Each
PointSetIteratoris associated with a given point set and maintains a current point index i and a current coordinate index j, which are both initialized to zero.
Successive coordinates can be accessed one or many at a time by the methods
nextCoordinates, respectively. The current coordinate index j can be set explicitely by
resetCurCoordIndex. Similar methods are available for resetting and accessing the current point. The method
nextPointpermits one to enumerate the successive points in natural order.
This class also implements the
RandomStreaminterface. This permits one to replace random numbers by the coordinates of (randomized) quasi-Monte Carlo points without changing the code that calls the generators in a simulation program. That is, the same simulation program can be used for both Monte Carlo and quasi-Monte Carlo simulations. The method
nextDoubledoes exactly the same as
nextCoordinate, it returns the current coordinate of the current point and advances the current coordinate by one. The substreams correspond to the points, so
resetStartSubstreamresets the current point coordinate to zero,
resetNextSubstreamresets the iterator to the next point, and
resetStartStreamresets the iterator to the first point of the point set.
There can be several iterators over the same point set. These iterators are independent from each other. Classes that implement this interface must maintain enough information so that each iterator is unaffected by other iterator's operations. However, the iterator does not need to be independent of the underlying point set. If the point set is modified (e.g., randomized), the iterator may continue to work as usual.
Point set iterators are implemented as inner classes because this gives a direct access to the private members (or variables) of the class. This is important for efficiency. They are quite similar to the iterators in Java collections.