From 5fafe835cb41f741f087a5d14891d45f8347562f Mon Sep 17 00:00:00 2001 From: dehnert Date: Thu, 7 Sep 2017 14:56:32 +0200 Subject: [PATCH] started on some optimizations for conditionals in MDPs --- .../prctl/helper/SparseMdpPrctlHelper.cpp | 39 +++++++++++++++---- src/storm/utility/graph.h | 2 +- 2 files changed, 33 insertions(+), 8 deletions(-) diff --git a/src/storm/modelchecker/prctl/helper/SparseMdpPrctlHelper.cpp b/src/storm/modelchecker/prctl/helper/SparseMdpPrctlHelper.cpp index 3c213b1cf..af195ac4a 100644 --- a/src/storm/modelchecker/prctl/helper/SparseMdpPrctlHelper.cpp +++ b/src/storm/modelchecker/prctl/helper/SparseMdpPrctlHelper.cpp @@ -975,18 +975,29 @@ namespace storm { } } + storm::storage::BitVector allStates(fixedTargetStates.size(), true); + + // Extend the target states by computing all states that have probability 1 to go to a target state + // under *all* schedulers. + fixedTargetStates = storm::utility::graph::performProb1A(transitionMatrix, transitionMatrix.getRowGroupIndices(), backwardTransitions, allStates, fixedTargetStates); + // We solve the max-case and later adjust the result if the optimization direction was to minimize. storm::storage::BitVector initialStatesBitVector(transitionMatrix.getRowGroupCount()); initialStatesBitVector.set(initialState); - storm::storage::BitVector allStates(initialStatesBitVector.size(), true); - std::vector conditionProbabilities = std::move(computeUntilProbabilities(OptimizationDirection::Maximize, transitionMatrix, backwardTransitions, allStates, conditionStates, false, false, minMaxLinearEquationSolverFactory).values); + // Extend the condition states by computing all states that have probability 1 to go to a condition state + // under *all* schedulers. + storm::storage::BitVector extendedConditionStates = storm::utility::graph::performProb1A(transitionMatrix, transitionMatrix.getRowGroupIndices(), backwardTransitions, allStates, conditionStates); + + STORM_LOG_DEBUG("Computing probabilities to satisfy condition."); + std::vector conditionProbabilities = std::move(computeUntilProbabilities(OptimizationDirection::Maximize, transitionMatrix, backwardTransitions, allStates, extendedConditionStates, false, false, minMaxLinearEquationSolverFactory).values); // If the conditional probability is undefined for the initial state, we return directly. if (storm::utility::isZero(conditionProbabilities[initialState])) { return std::unique_ptr(new ExplicitQuantitativeCheckResult(initialState, storm::utility::infinity())); } + STORM_LOG_DEBUG("Computing probabilities to reach target."); std::vector targetProbabilities = std::move(computeUntilProbabilities(OptimizationDirection::Maximize, transitionMatrix, backwardTransitions, allStates, fixedTargetStates, false, false, minMaxLinearEquationSolverFactory).values); storm::storage::BitVector statesWithProbabilityGreater0E(transitionMatrix.getRowGroupCount(), true); @@ -999,10 +1010,15 @@ namespace storm { } // Determine those states that need to be equipped with a restart mechanism. - storm::storage::BitVector problematicStates = storm::utility::graph::performProb0E(transitionMatrix, transitionMatrix.getRowGroupIndices(), backwardTransitions, allStates, conditionStates | fixedTargetStates); + STORM_LOG_DEBUG("Computing problematic states."); + storm::storage::BitVector pureResetStates = storm::utility::graph::performProb0A(backwardTransitions, allStates, fixedTargetStates); + + // FIXME: target | condition as target states here? + storm::storage::BitVector problematicStates = storm::utility::graph::performProb0E(transitionMatrix, transitionMatrix.getRowGroupIndices(), backwardTransitions, allStates, fixedTargetStates); // Otherwise, we build the transformed MDP. - storm::storage::BitVector relevantStates = storm::utility::graph::getReachableStates(transitionMatrix, initialStatesBitVector, allStates, conditionStates | fixedTargetStates); + storm::storage::BitVector relevantStates = storm::utility::graph::getReachableStates(transitionMatrix, initialStatesBitVector, allStates, extendedConditionStates | fixedTargetStates | pureResetStates); + STORM_LOG_TRACE("Found " << relevantStates.getNumberOfSetBits() << " relevant states for conditional probability computation."); std::vector numberOfStatesBeforeRelevantStates = relevantStates.getNumberOfSetBitsBeforeIndices(); storm::storage::sparse::state_type newGoalState = relevantStates.getNumberOfSetBits(); storm::storage::sparse::state_type newStopState = newGoalState + 1; @@ -1014,17 +1030,24 @@ namespace storm { for (auto state : relevantStates) { builder.newRowGroup(currentRow); if (fixedTargetStates.get(state)) { - builder.addNextValue(currentRow, newGoalState, conditionProbabilities[state]); if (!storm::utility::isZero(conditionProbabilities[state])) { + builder.addNextValue(currentRow, newGoalState, conditionProbabilities[state]); + } + if (!storm::utility::isOne(conditionProbabilities[state])) { builder.addNextValue(currentRow, newFailState, storm::utility::one() - conditionProbabilities[state]); } ++currentRow; - } else if (conditionStates.get(state)) { - builder.addNextValue(currentRow, newGoalState, targetProbabilities[state]); + } else if (extendedConditionStates.get(state)) { if (!storm::utility::isZero(targetProbabilities[state])) { + builder.addNextValue(currentRow, newGoalState, targetProbabilities[state]); + } + if (!storm::utility::isOne(targetProbabilities[state])) { builder.addNextValue(currentRow, newStopState, storm::utility::one() - targetProbabilities[state]); } ++currentRow; + } else if (pureResetStates.get(state)) { + builder.addNextValue(currentRow, numberOfStatesBeforeRelevantStates[initialState], storm::utility::one()); + ++currentRow; } else { for (uint_fast64_t row = transitionMatrix.getRowGroupIndices()[state]; row < transitionMatrix.getRowGroupIndices()[state + 1]; ++row) { for (auto const& successorEntry : transitionMatrix.getRow(row)) { @@ -1051,9 +1074,11 @@ namespace storm { ++currentRow; // Finally, build the matrix and dispatch the query as a reachability query. + STORM_LOG_DEBUG("Computing conditional probabilties."); storm::storage::BitVector newGoalStates(newFailState + 1); newGoalStates.set(newGoalState); storm::storage::SparseMatrix newTransitionMatrix = builder.build(); + STORM_LOG_DEBUG("Transformed model has " << newTransitionMatrix.getRowGroupCount() << " states and " << newTransitionMatrix.getNonzeroEntryCount() << " transitions."); storm::storage::SparseMatrix newBackwardTransitions = newTransitionMatrix.transpose(true); std::vector goalProbabilities = std::move(computeUntilProbabilities(OptimizationDirection::Maximize, newTransitionMatrix, newBackwardTransitions, storm::storage::BitVector(newFailState + 1, true), newGoalStates, false, false, minMaxLinearEquationSolverFactory).values); diff --git a/src/storm/utility/graph.h b/src/storm/utility/graph.h index 010e68feb..d0f3dde15 100644 --- a/src/storm/utility/graph.h +++ b/src/storm/utility/graph.h @@ -416,7 +416,7 @@ namespace storm { storm::storage::BitVector performProb1A(storm::models::sparse::NondeterministicModel const& model, storm::storage::SparseMatrix const& backwardTransitions, storm::storage::BitVector const& phiStates, storm::storage::BitVector const& psiStates); template - storm::storage::BitVector performProb1A( storm::storage::SparseMatrix const& transitionMatrix, std::vector const& nondeterministicChoiceIndices, storm::storage::SparseMatrix const& backwardTransitions, storm::storage::BitVector const& phiStates, storm::storage::BitVector const& psiStates); + storm::storage::BitVector performProb1A(storm::storage::SparseMatrix const& transitionMatrix, std::vector const& nondeterministicChoiceIndices, storm::storage::SparseMatrix const& backwardTransitions, storm::storage::BitVector const& phiStates, storm::storage::BitVector const& psiStates); template std::pair performProb01Min(storm::storage::SparseMatrix const& transitionMatrix, std::vector const& nondeterministicChoiceIndices, storm::storage::SparseMatrix const& backwardTransitions, storm::storage::BitVector const& phiStates, storm::storage::BitVector const& psiStates) ;