Tweak comments in policy iteration.

git-svn-id: https://www.prismmodelchecker.org/svn/prism/prism/trunk@5632 bbc10eb1-c90d-0410-af57-cb519fbb1720

prism/src/explicit/MDPModelChecker.java

@@ -819,7 +819,8 @@ public class MDPModelChecker extends ProbModelChecker
 			done = true;
 			diff = 0;
 			for (i = 0; i < n; i++) {
-				// NB: We must not check 'no' states (may look non-optimal)
+				// Don't look at no/yes states - we don't store adversary info for them,
+				// so they might appear non-optimal
 				if (no.get(i) || yes.get(i))
 					continue;
 				if (!PrismUtils.doublesAreClose(soln[i], soln2[i], termCritParam, termCrit == TermCrit.ABSOLUTE)) {
@@ -860,7 +861,7 @@ public class MDPModelChecker extends ProbModelChecker
 		double soln[], soln2[];
 		boolean done;
 		long timer;
-		int policy[];
+		int adv[];
 		DTMCModelChecker mcDTMC;
 		DTMC dtmc;
 
@@ -887,18 +888,18 @@ public class MDPModelChecker extends ProbModelChecker
 		for (i = 0; i < n; i++)
 			soln[i] = soln2[i] = yes.get(i) ? 1.0 : 0.0;
 
-		// Generate initial policy
-		policy = new int[n];
+		// Generate initial adversary
+		adv = new int[n];
 		for (i = 0; i < n; i++)
-			policy[i] = 0;
+			adv[i] = 0;
 
 		// Start iterations
 		iters = totalIters = 0;
 		done = false;
 		while (!done) {
 			iters++;
-			// Solve policy
-			dtmc = new DTMCFromMDPMemorylessAdversary(mdp, policy);
+			// Solve induced DTMC for adversary
+			dtmc = new DTMCFromMDPMemorylessAdversary(mdp, adv);
 			res = mcDTMC.computeReachProbsGaussSeidel(dtmc, no, yes, soln, null);
 			soln = res.soln;
 			totalIters += res.numIters;
@@ -907,14 +908,15 @@ public class MDPModelChecker extends ProbModelChecker
 			done = true;
 			diff = 0;
 			for (i = 0; i < n; i++) {
-				// NB: We must not check 'no' states (may look non-optimal)
+				// Don't look at no/yes states - we don't store adversary info for them,
+				// so they might appear non-optimal
 				if (no.get(i) || yes.get(i))
 					continue;
 				if (!PrismUtils.doublesAreClose(soln[i], soln2[i], termCritParam, termCrit == TermCrit.ABSOLUTE)) {
 					done = false;
 					diff++;
 					List<Integer> opt = mdp.mvMultMinMaxSingleChoices(i, soln, min, soln2[i]);
-					policy[i] = opt.get(0);
+					adv[i] = opt.get(0);
 				}
 			}
 		}