/**
* Remaps the stratifications from one stratification set to another, combining the values in V
* according to the combiner function.
*
* <p>stratifierToReplace defines a set of states S1, while newStratifier defines a new set S2.
* remappedStates is a map from all of S1 into at least some of S2. This function creates a new,
* fully initialized manager where all of the data in this new manager is derived from the
* original data in this object combined according to the mapping remappedStates. When multiple
* elements of S1 can map to the same value in S2, these are sequentially combined by the function
* combiner. Suppose for example at states s1, s2, and s3 all map to N1. Eventually the value
* associated with state N1 would be
*
* <p>value(N1) = combine(value(s1), combine(value(s2), value(s3))
*
* <p>in some order for s1, s2, and s3, which is not defined. Note that this function only
* supports combining one stratification at a time, but in principle a loop over stratifications
* and this function could do the multi-dimensional collapse.
*
* @param stratifierToReplace
* @param newStratifier
* @param combiner
* @param remappedStates
* @return
*/
public StratificationManager<K, V> combineStrats(
final K stratifierToReplace,
final K newStratifier,
final Combiner<V> combiner,
final Map<Object, Object> remappedStates) {
// make sure the mapping is reasonable
if (!newStratifier.getAllStates().containsAll(remappedStates.values()))
throw new ReviewedGATKException(
"combineStrats: remapped states contains states not found in newStratifer state set");
if (!remappedStates.keySet().containsAll(stratifierToReplace.getAllStates()))
throw new ReviewedGATKException(
"combineStrats: remapped states missing mapping for some states");
// the new strats are the old ones with the single replacement
final List<K> newStrats = new ArrayList<K>(getStratifiers());
final int stratOffset = newStrats.indexOf(stratifierToReplace);
if (stratOffset == -1)
throw new ReviewedGATKException(
"Could not find strat to replace "
+ stratifierToReplace
+ " in existing strats "
+ newStrats);
newStrats.set(stratOffset, newStratifier);
// create an empty but fully initialized new manager
final StratificationManager<K, V> combined = new StratificationManager<K, V>(newStrats);
// for each key, get its state, update it according to the map, and update the combined manager
for (int key = 0; key < size(); key++) {
// the new state is just the old one with the replacement
final List<Object> newStates = new ArrayList<Object>(getStatesForKey(key));
final Object oldState = newStates.get(stratOffset);
final Object newState = remappedStates.get(oldState);
newStates.set(stratOffset, newState);
// look up the new key given the new state
final int combinedKey = combined.getKey(newStates);
if (combinedKey == -1)
throw new ReviewedGATKException(
"Couldn't find key for states: " + Utils.join(",", newStates));
// combine the old value with whatever new value is in combined already
final V combinedValue = combiner.combine(combined.get(combinedKey), get(key));
// update the value associated with combined key
combined.set(combinedKey, combinedValue);
}
return combined;
}
/**
* Recursive construction helper for main constructor that fills into the complete tree of
* StratNodes. This function returns the complete tree suitable for associating data with each
* combinatino of keys. Note that the tree is not fully complete as the keys are not yet set for
* each note (see assignStratifierValuesByKey)
*
* @param strats
* @return
*/
private StratNode<K> buildStratificationTree(final Queue<K> strats) {
final K first = strats.poll();
if (first == null) {
// we are at a leaf
return new StratNode<K>();
} else {
// we are in the middle of the tree
final Collection<Object> states = first.getAllStates();
if (states.isEmpty()) throw new ReviewedGATKException("State " + first + " is empty!");
final LinkedHashMap<Object, StratNode<K>> subNodes =
new LinkedHashMap<Object, StratNode<K>>(states.size());
for (final Object state : states) {
// have to copy because poll modifies the queue
final Queue<K> copy = new LinkedList<K>(strats);
subNodes.put(state, buildStratificationTree(copy));
}
return new StratNode<K>(first, subNodes);
}
}
