// -------------------------------------------------------------------------------------------- static void ProcessNode(PositionEvalCache cache, MCTSNode node, float weightEmpirical, bool saveToCache, bool rewriteNodeInTree) { Span <MCTSNodeStructChild> children = node.Ref.Children; // TODO: optimize this away if saveToCache is false ushort[] probabilities = new ushort[node.NumPolicyMoves]; ushort[] indices = new ushort[node.NumPolicyMoves]; // Compute empirical visit distribution float[] nodeFractions = new float[node.NumPolicyMoves]; for (int i = 0; i < node.NumChildrenExpanded; i++) { nodeFractions[i] = (float)node.ChildAtIndex(i).N / (float)node.N; } // Determine P of first unexpanded node // We can't allow any child to have a new P less than this // since we need to keep them in order by P and the resorting logic below // can only operate over expanded nodes float minP = 0; if (node.NumChildrenExpanded < node.NumPolicyMoves) { minP = node.ChildAtIndexInfo(node.NumChildrenExpanded).p; } // Add each move to the policy vector with blend of prior and empirical values for (int i = 0; i < node.NumChildrenExpanded; i++) { (MCTSNode node, EncodedMove move, FP16 p)info = node.ChildAtIndexInfo(i); indices[i] = (ushort)info.move.IndexNeuralNet; float newValue = (1.0f - weightEmpirical) * info.p + weightEmpirical * nodeFractions[i]; if (newValue < minP) { newValue = minP; } probabilities[i] = CompressedPolicyVector.EncodedProbability(newValue); if (rewriteNodeInTree && weightEmpirical != 0) { MCTSNodeStructChild thisChild = children[i]; if (thisChild.IsExpanded) { ref MCTSNodeStruct childNodeRef = ref thisChild.ChildRef; thisChild.ChildRef.P = (FP16)newValue; } else { node.Ref.ChildAtIndex(i).SetUnexpandedPolicyValues(thisChild.Move, (FP16)newValue); } } }
/// <summary> /// Implements the gathering of nodes up to speecified maximum depth and width. /// </summary> /// <param name="selectorID"></param> /// <param name="node"></param> /// <param name="maxNodes"></param> /// <param name="maxDepth"></param> /// <param name="width"></param> /// <param name="nodes"></param> /// <param name="pThreshold"></param> void GatherRootPreloadNodes(int selectorID, MCTSNode node, int maxNodes, int maxDepth, int width, List <MCTSNode> nodes, float pThreshold) { if (nodes.Count >= maxNodes) { return; } if (node.IsTranspositionLinked) { return; } // For each top child for (int i = 0; i < Math.Min(node.NumPolicyMoves, width); i++) { if (NumPreloaded >= MAX_PRELOAD_NODES_TOTAL) { return; } (MCTSNode childNode, EncodedMove move, FP16 p) = node.ChildAtIndexInfo(i); if (float.IsNaN(pThreshold) || p >= pThreshold) { // Add this node if not already extant if (childNode == null) { // Create this child (as cache only) and update in flight childNode = node.CreateChild(i); childNode.ActionType = MCTSNode.NodeActionType.CacheOnly; if (selectorID == 0) { childNode.Ref.BackupIncrementInFlight(1, 0); } else { childNode.Ref.BackupIncrementInFlight(0, 1); } nodes.Add(childNode); NumPreloaded++; if (nodes.Count == maxNodes) { return; } } else { node.Annotate(); if (node.Depth < maxDepth - 1 && childNode.N > 0) { // Recursively descend Debug.Assert(childNode != null); GatherRootPreloadNodes(selectorID, childNode, maxNodes, maxDepth, width, nodes, pThreshold); } } } } }
void OutputUCIInfo(MCTSManager manager, MCTSNode searchRootNode, bool isFinalInfo = false) { BestMoveInfo best = searchRootNode.BestMoveInfo(false); if (numPV == 1) { UCIWriteLine(UCIInfo.UCIInfoString(manager, searchRootNode, best?.BestMoveNode, showWDL: showWDL, scoreAsQ: scoreAsQ)); } else { // Send top move UCIWriteLine(UCIInfo.UCIInfoString(manager, searchRootNode, best.BestMoveNode, 1, showWDL: showWDL, useParentN: !perPVCounters, scoreAsQ: scoreAsQ)); // Send other moves visited MCTSNode[] sortedN = searchRootNode.ChildrenSorted(s => - (float)s.N); int multiPVIndex = 2; for (int i = 0; i < sortedN.Length && i < numPV; i++) { if (!object.ReferenceEquals(sortedN[i], best.BestMoveNode)) { UCIWriteLine(UCIInfo.UCIInfoString(manager, searchRootNode, sortedN[i], multiPVIndex, showWDL: showWDL, useParentN: !perPVCounters, scoreAsQ: scoreAsQ)); multiPVIndex++; } } // Finally show moves that had no visits float elapsedTimeSeconds = (float)(DateTime.Now - manager.StartTimeThisSearch).TotalSeconds; string timeStr = $"{ elapsedTimeSeconds * 1000.0f:F0}"; for (int i = multiPVIndex - 1; i < searchRootNode.NumPolicyMoves; i++) { (MCTSNode node, EncodedMove move, FP16 p)info = searchRootNode.ChildAtIndexInfo(i); if (info.node == null) { bool isWhite = searchRootNode.Annotation.Pos.MiscInfo.SideToMove == SideType.White; EncodedMove moveCorrectPerspective = isWhite ? info.move : info.move.Flipped; string str = $"info depth 0 seldepth 0 time { timeStr } nodes 1 score cp 0 tbhits 0 " + $"multipv {multiPVIndex} pv {moveCorrectPerspective.AlgebraicStr} "; UCIWriteLine(str); multiPVIndex++; } } } if (verboseMoveStats && (logLiveStats || isFinalInfo)) { OutputVerboseMoveStats(CeresEngine.Search.SearchRootNode); } }
static MCTSNode DescendMovesToNode(MCTSNode rootNode, List <MGMove> moves) { MCTSNode node = rootNode; foreach (MGMove move in moves) { int?childIndex = node.Ref.ChildIndexWithMove(move); if (childIndex is null) { throw new Exception($"Move {move} not found at node {node}"); } else { (node, _, _) = node.ChildAtIndexInfo(childIndex.Value); } } return(node); }
public static List <LC0VerboseMoveStat> BuildStats(MCTSNode searchRootNode) { List <LC0VerboseMoveStat> stats = new List <LC0VerboseMoveStat>(); BestMoveInfo best = searchRootNode.BestMoveInfo(false); // First process policy moves not yet expanded // starting from last one (lowest probability). for (int i = searchRootNode.NumPolicyMoves - 1; i >= 0; i--) { (MCTSNode node, EncodedMove move, FP16 p)info = searchRootNode.ChildAtIndexInfo(i); if (info.node == null) { LC0VerboseMoveStat stat = BuildStatNotExpanded(searchRootNode, i); stats.Add(stat); } } // Now process moves expanded in order of visit count. MCTSNode[] sortedN = searchRootNode.ChildrenSorted(s => (float)s.N + 0.0001f * s.P); foreach (MCTSNode node in sortedN) { if (!object.ReferenceEquals(node, best.BestMoveNode)) { stats.Add(BuildStatExpanded(node, false)); } } // Save the best move for last. stats.Add(BuildStatExpanded(best.BestMoveNode, false)); // Finally, output the search root node. stats.Add(BuildStatExpanded(searchRootNode, true)); return(stats); }