imported patch JDD-SplitByValue.patch

prism/src/jdd/JDD.java

@@ -977,6 +977,44 @@ public class JDD
 		return rv;
 	}
 
+	/**
+	 * Splits the given MTBDD by the different values that can be
+	 * occur for those valuations that match {@code filter}.<br>
+	 * Returns a TreeMap with the double values as the keys and
+	 * a 0/1-MTBDD for the valuations in {@code dd} that satisfy {@code filter}
+	 * and map to the given key as the value.
+	 * <br>[ REFS: <i>result (value JDDNodes in the map)</i>, DEREFS: dd, filter ]
+	 */
+	public static TreeMap<Double, JDDNode> SplitByValue(JDDNode dd, JDDNode filter)
+	{
+		TreeMap<Double, JDDNode> result = new TreeMap<>();
+
+		// As long as the filter is non-empty...
+		while (!filter.equals(ZERO)) {
+			// set all values outside of the filter to +infty
+			dd = JDD.ITE(filter.copy(), dd, JDD.PLUS_INFINITY.copy());
+
+			// find the minimum value
+			double value = FindMin(dd);
+			// extract the 0/1-MTBDD with the valuations that lead to this value
+			JDDNode ddWithValue = Equals(dd.copy(), value);
+			if (value == Double.POSITIVE_INFINITY) {
+				// ensure that we only get those valuations that match filter
+				ddWithValue = JDD.And(ddWithValue, filter.copy());
+			}
+			// store in map
+			result.put(value, ddWithValue);
+			// update filter to remove all valuations that were put in the map
+			filter = JDD.And(filter, Not(ddWithValue.copy()));
+		}
+
+		// cleanup
+		JDD.Deref(dd);
+		JDD.Deref(filter);
+
+		return result;
+	}
+
 	/**
 	 * returns dd restricted to first non-zero path (cube)
 	 * <br>[ REFS: <i>result</i>, DEREFS: dd ]