use of com.tencent.angel.ml.GBDT.algo.tree.SplitEntry in project angel by Tencent.
the class GradHistHelper method findSplitOfFeature.
// find the best split result of one feature from a server row, used by the PS
public static SplitEntry findSplitOfFeature(int fid, ServerIntDoubleRow row, int startIdx, GBDTParam param) {
LOG.debug(String.format("Find best split for fid[%d] in histogram size[%d], startIdx[%d]", fid, row.size(), startIdx));
SplitEntry splitEntry = new SplitEntry();
// 1. set the feature id
splitEntry.setFid(fid);
// 2. create the best left stats and right stats
GradStats bestLeftStat = new GradStats();
GradStats bestRightStat = new GradStats();
GradStats rootStats = calGradStats(row, startIdx, param.numSplit);
if (startIdx + 2 * param.numSplit <= row.getEndCol()) {
// 3. the gain of the root node
float rootGain = rootStats.calcGain(param);
// 4. create the temp left and right grad stats
GradStats leftStats = new GradStats();
GradStats rightStats = new GradStats();
// 5. loop over all the data in histogram
for (int histIdx = startIdx; histIdx < startIdx + param.numSplit; histIdx++) {
// 5.1. get the grad and hess of current hist bin
float grad = (float) row.get(histIdx);
float hess = (float) row.get(param.numSplit + histIdx);
leftStats.add(grad, hess);
// 5.2. check whether we can split with current left hessian
if (leftStats.sumHess >= param.minChildWeight) {
// right = root - left
rightStats.setSubstract(rootStats, leftStats);
// 5.3. check whether we can split with current right hessian
if (rightStats.sumHess >= param.minChildWeight) {
// 5.4. calculate the current loss gain
float lossChg = leftStats.calcGain(param) + rightStats.calcGain(param) - rootGain;
// 5.5. check whether we should update the split result with current loss gain
// split rule: value <= split
int splitIdx = histIdx - startIdx;
// the task use index to find fvalue
if (splitEntry.update(lossChg, fid, splitIdx)) {
// 5.6. if should update, also update the best left and right grad stats
bestLeftStat.update(leftStats.sumGrad, leftStats.sumHess);
bestRightStat.update(rightStats.sumGrad, rightStats.sumHess);
}
}
}
}
// 6. set the best left and right grad stats
splitEntry.leftGradStat = bestLeftStat;
splitEntry.rightGradStat = bestRightStat;
} else {
LOG.error("index out of grad histogram size.");
}
return splitEntry;
}
use of com.tencent.angel.ml.GBDT.algo.tree.SplitEntry in project angel by Tencent.
the class GBDTGradHistGetRowFunc method merge.
@Override
public GetResult merge(List<PartitionGetResult> partResults) {
int size = partResults.size();
List<ServerRow> rowSplits = new ArrayList<ServerRow>(size);
for (int i = 0; i < size; i++) {
rowSplits.add(((PartitionGetRowResult) partResults.get(i)).getRowSplit());
}
SplitEntry splitEntry = new SplitEntry();
for (int i = 0; i < size; i++) {
ServerIntDoubleRow row = (ServerIntDoubleRow) ((PartitionGetRowResult) partResults.get(i)).getRowSplit();
int fid = (int) row.get(0 + (int) row.getStartCol());
if (fid != -1) {
int splitIndex = (int) row.get(1 + (int) row.getStartCol());
float lossGain = (float) row.get(2 + (int) row.getStartCol());
float leftSumGrad = (float) row.get(3 + (int) row.getStartCol());
float leftSumHess = (float) row.get(4 + (int) row.getStartCol());
float rightSumGrad = (float) row.get(5 + (int) row.getStartCol());
float rightSumHess = (float) row.get(6 + (int) row.getStartCol());
LOG.info(String.format("psFunc: the best split after looping a split: fid[%d], fvalue[%d], loss gain[%f]" + ", leftSumGrad[%f], leftSumHess[%f], rightSumGrad[%f], rightSumHess[%f]", fid, splitIndex, lossGain, leftSumGrad, leftSumHess, rightSumGrad, rightSumHess));
GradStats curLeftGradStat = new GradStats(leftSumGrad, leftSumHess);
GradStats curRightGradStat = new GradStats(rightSumGrad, rightSumHess);
SplitEntry curSplitEntry = new SplitEntry(fid, splitIndex, lossGain);
curSplitEntry.leftGradStat = curLeftGradStat;
curSplitEntry.rightGradStat = curRightGradStat;
splitEntry.update(curSplitEntry);
}
}
return new GBDTGradHistGetRowResult(ResponseType.SUCCESS, splitEntry);
}
use of com.tencent.angel.ml.GBDT.algo.tree.SplitEntry in project angel by Tencent.
the class AfterSplitThread method run.
@Override
public void run() {
int splitFeature = splitFeatureVec.get(nid);
float splitValue = (float) splitValueVec.get(nid);
float splitGain = (float) splitGainVec.get(nid);
float nodeSumGrad = (float) nodeGradStatsVec.get(nid);
float nodeSumHess = (float) nodeGradStatsVec.get(nid + this.controller.maxNodeNum);
LOG.info(String.format("Active node[%d]: split feature[%d] value[%f], lossChg[%f], sumGrad[%f], sumHess[%f]", nid, splitFeature, splitValue, splitGain, nodeSumGrad, nodeSumHess));
if (splitFeature != -1) {
// 5.1. set the children nodes of this node
this.controller.forest[this.controller.currentTree].nodes.get(nid).setLeftChild(2 * nid + 1);
this.controller.forest[this.controller.currentTree].nodes.get(nid).setRightChild(2 * nid + 2);
// 5.2. set split info and grad stats to this node
SplitEntry splitEntry = new SplitEntry(splitFeature, splitValue, splitGain);
this.controller.forest[this.controller.currentTree].stats.get(nid).setSplitEntry(splitEntry);
this.controller.forest[this.controller.currentTree].stats.get(nid).lossChg = splitGain;
this.controller.forest[this.controller.currentTree].stats.get(nid).setStats(nodeSumGrad, nodeSumHess);
// 5.2. create children nodes
TNode leftChild = new TNode(2 * nid + 1, nid, -1, -1);
TNode rightChild = new TNode(2 * nid + 2, nid, -1, -1);
this.controller.forest[this.controller.currentTree].nodes.set(2 * nid + 1, leftChild);
this.controller.forest[this.controller.currentTree].nodes.set(2 * nid + 2, rightChild);
LOG.debug(String.format("Add children nodes: %d and %d", 2 * nid + 1, 2 * nid + 2));
// 5.3. create node stats for children nodes, and add them to the tree
RegTNodeStat leftChildStat = new RegTNodeStat(this.controller.param);
RegTNodeStat rightChildStat = new RegTNodeStat(this.controller.param);
float leftChildSumGrad = (float) nodeGradStatsVec.get(2 * nid + 1);
float rightChildSumGrad = (float) nodeGradStatsVec.get(2 * nid + 2);
float leftChildSumHess = (float) nodeGradStatsVec.get(2 * nid + 1 + this.controller.maxNodeNum);
float rightChildSumHess = (float) nodeGradStatsVec.get(2 * nid + 2 + this.controller.maxNodeNum);
leftChildStat.setStats(leftChildSumGrad, leftChildSumHess);
rightChildStat.setStats(rightChildSumGrad, rightChildSumHess);
this.controller.forest[this.controller.currentTree].stats.set(2 * nid + 1, leftChildStat);
this.controller.forest[this.controller.currentTree].stats.set(2 * nid + 2, rightChildStat);
// 5.4. reset instance position
this.controller.updateTrainInsPos(this.nid, splitFeature, splitValue);
// 5.5. add new active nodes if possible, inc depth, otherwise finish this tree
if (this.controller.currentDepth < this.controller.param.maxDepth - 1) {
LOG.debug(String.format("Add children nodes of node[%d]:[%d][%d] to active nodes", nid, 2 * nid + 1, 2 * nid + 2));
this.controller.addActiveNode(2 * nid + 1);
this.controller.addActiveNode(2 * nid + 2);
} else {
// 5.6. set children nodes to leaf nodes
LOG.debug(String.format("Set children nodes of node[%d]:[%d][%d] to leaf nodes", nid, 2 * nid + 1, 2 * nid + 2));
this.controller.setNodeToLeaf(2 * nid + 1, leftChildStat.baseWeight);
this.controller.setNodeToLeaf(2 * nid + 2, rightChildStat.baseWeight);
}
} else {
// 5.7. set nid to leaf node
this.controller.setNodeToLeaf(nid, this.controller.param.calcWeight(nodeSumGrad, nodeSumHess));
LOG.debug(String.format("Set node %d to leaf", nid));
}
// 5.8. deactivate active node
this.controller.resetActiveTNodes(nid);
}
use of com.tencent.angel.ml.GBDT.algo.tree.SplitEntry in project angel by Tencent.
the class GBDTController method findSplit.
// find split
public void findSplit() throws Exception {
LOG.info("------Find split------");
long startTime = System.currentTimeMillis();
// 1. find responsible tree node, using RR scheme
List<Integer> responsibleTNode = new ArrayList<>();
int activeTNodeNum = 0;
for (int nid = 0; nid < this.activeNode.length; nid++) {
int isActive = this.activeNode[nid];
if (isActive == 1) {
if (this.taskContext.getTaskIndex() == activeTNodeNum) {
responsibleTNode.add(nid);
}
if (++activeTNodeNum >= taskContext.getTotalTaskNum()) {
activeTNodeNum = 0;
}
}
}
int[] tNodeId = Maths.intList2Arr(responsibleTNode);
LOG.info(String.format("Task[%d] responsible tree node: %s", this.taskContext.getTaskId().getIndex(), responsibleTNode.toString()));
// 2. pull gradient histogram
// the updated indices of the parameter on PS
int[] updatedIndices = new int[tNodeId.length];
// the updated split features
int[] updatedSplitFid = new int[tNodeId.length];
// the updated split value
double[] updatedSplitFvalue = new double[tNodeId.length];
// the updated split gain
double[] updatedSplitGain = new double[tNodeId.length];
boolean isServerSplit = taskContext.getConf().getBoolean(MLConf.ML_GBDT_SERVER_SPLIT(), MLConf.DEFAULT_ML_GBDT_SERVER_SPLIT());
int splitNum = taskContext.getConf().getInt(MLConf.ML_GBDT_SPLIT_NUM(), MLConf.DEFAULT_ML_GBDT_SPLIT_NUM());
for (int i = 0; i < tNodeId.length; i++) {
int nid = tNodeId[i];
LOG.debug(String.format("Task[%d] find best split of tree node: %d", this.taskContext.getTaskIndex(), nid));
// 2.1. get the name of this node's gradient histogram on PS
String gradHistName = this.param.gradHistNamePrefix + nid;
// 2.2. pull the histogram
long pullStartTime = System.currentTimeMillis();
PSModel histMat = model.getPSModel(gradHistName);
IntDoubleVector histogram = null;
SplitEntry splitEntry = null;
if (isServerSplit) {
int matrixId = histMat.getMatrixId();
GBDTGradHistGetRowFunc func = new GBDTGradHistGetRowFunc(new HistAggrParam(matrixId, 0, param.numSplit, param.minChildWeight, param.regAlpha, param.regLambda));
splitEntry = ((GBDTGradHistGetRowResult) histMat.get(func)).getSplitEntry();
} else {
histogram = (IntDoubleVector) histMat.getRow(0);
LOG.debug("Get grad histogram without server split mode, histogram size" + histogram.getDim());
}
LOG.info(String.format("Pull histogram from PS cost %d ms", System.currentTimeMillis() - pullStartTime));
GradHistHelper histHelper = new GradHistHelper(this, nid);
// 2.3. find best split result of this tree node
if (this.param.isServerSplit) {
// 2.3.1 using server split
if (splitEntry.getFid() != -1) {
int trueSplitFid = this.fSet[splitEntry.getFid()];
int splitIdx = (int) splitEntry.getFvalue();
float trueSplitValue = this.sketches[trueSplitFid * this.param.numSplit + splitIdx];
LOG.info(String.format("Best split of node[%d]: feature[%d], value[%f], " + "true feature[%d], true value[%f], losschg[%f]", nid, splitEntry.getFid(), splitEntry.getFvalue(), trueSplitFid, trueSplitValue, splitEntry.getLossChg()));
splitEntry.setFid(trueSplitFid);
splitEntry.setFvalue(trueSplitValue);
}
// update the grad stats of the root node on PS, only called once by leader worker
if (nid == 0) {
GradStats rootStats = new GradStats(splitEntry.leftGradStat);
rootStats.add(splitEntry.rightGradStat);
this.updateNodeGradStats(nid, rootStats);
}
// update the grad stats of children node
if (splitEntry.fid != -1) {
// update the left child
this.updateNodeGradStats(2 * nid + 1, splitEntry.leftGradStat);
// update the right child
this.updateNodeGradStats(2 * nid + 2, splitEntry.rightGradStat);
}
// 2.3.2 the updated split result (tree node/feature/value/gain) on PS,
updatedIndices[i] = nid;
updatedSplitFid[i] = splitEntry.fid;
updatedSplitFvalue[i] = splitEntry.fvalue;
updatedSplitGain[i] = splitEntry.lossChg;
} else {
// 2.3.3 otherwise, the returned histogram contains the gradient info
splitEntry = histHelper.findBestSplit(histogram);
LOG.info(String.format("Best split of node[%d]: feature[%d], value[%f], losschg[%f]", nid, splitEntry.getFid(), splitEntry.getFvalue(), splitEntry.getLossChg()));
// 2.3.4 the updated split result (tree node/feature/value/gain) on PS,
updatedIndices[i] = nid;
updatedSplitFid[i] = splitEntry.fid;
updatedSplitFvalue[i] = splitEntry.fvalue;
updatedSplitGain[i] = splitEntry.lossChg;
}
// 2.3.5 reset this tree node's gradient histogram to 0
histMat.zero();
}
// 3. push split feature to PS
IntIntVector splitFeatureVector = new IntIntVector(this.activeNode.length, new IntIntDenseVectorStorage(this.activeNode.length));
// 4. push split value to PS
IntDoubleVector splitValueVector = new IntDoubleVector(this.activeNode.length, new IntDoubleDenseVectorStorage(this.activeNode.length));
// 5. push split gain to PS
IntDoubleVector splitGainVector = new IntDoubleVector(this.activeNode.length, new IntDoubleDenseVectorStorage(this.activeNode.length));
for (int i = 0; i < updatedIndices.length; i++) {
splitFeatureVector.set(updatedIndices[i], updatedSplitFid[i]);
splitValueVector.set(updatedIndices[i], updatedSplitFvalue[i]);
splitGainVector.set(updatedIndices[i], updatedSplitGain[i]);
}
PSModel splitFeat = model.getPSModel(this.param.splitFeaturesName);
splitFeat.increment(this.currentTree, splitFeatureVector);
PSModel splitValue = model.getPSModel(this.param.splitValuesName);
splitValue.increment(this.currentTree, splitValueVector);
PSModel splitGain = model.getPSModel(this.param.splitGainsName);
splitGain.increment(this.currentTree, splitGainVector);
// 6. set phase to AFTER_SPLIT
// this.phase = GBDTPhase.AFTER_SPLIT;
LOG.info(String.format("Find split cost: %d ms", System.currentTimeMillis() - startTime));
// clock
Set<String> needFlushMatrixSet = new HashSet<String>(3);
needFlushMatrixSet.add(this.param.splitFeaturesName);
needFlushMatrixSet.add(this.param.splitValuesName);
needFlushMatrixSet.add(this.param.splitGainsName);
needFlushMatrixSet.add(this.param.nodeGradStatsName);
clockAllMatrix(needFlushMatrixSet, true);
}
use of com.tencent.angel.ml.GBDT.algo.tree.SplitEntry in project angel by Tencent.
the class GradHistHelper method findBestSplitHelper.
// find the best split result of the histogram of a tree node
public static SplitEntry findBestSplitHelper(IntDoubleVector histogram) throws InterruptedException {
LOG.debug(String.format("------To find the best split of histogram size[%d]------", histogram.getDim()));
SplitEntry splitEntry = new SplitEntry();
LOG.debug(String.format("The best split before looping the histogram: fid[%d], fvalue[%f]", splitEntry.fid, splitEntry.fvalue));
int featureNum = WorkerContext.get().getConf().getInt(MLConf.ML_FEATURE_INDEX_RANGE(), MLConf.DEFAULT_ML_FEATURE_INDEX_RANGE());
int splitNum = WorkerContext.get().getConf().getInt(MLConf.ML_GBDT_SPLIT_NUM(), MLConf.DEFAULT_ML_GBDT_SPLIT_NUM());
if (histogram.getDim() != featureNum * 2 * splitNum) {
LOG.debug("The size of histogram is not equal to 2 * featureNum*splitNum.");
return splitEntry;
}
for (int fid = 0; fid < featureNum; fid++) {
// 2.2. get the indexes of histogram of this feature
int startIdx = 2 * splitNum * fid;
// 2.3. find the best split of current feature
SplitEntry curSplit = findBestSplitOfOneFeatureHelper(fid, histogram, startIdx);
// 2.4. update the best split result if possible
splitEntry.update(curSplit);
}
LOG.debug(String.format("The best split after looping the histogram: fid[%d], fvalue[%f], loss gain[%f]", splitEntry.fid, splitEntry.fvalue, splitEntry.lossChg));
return splitEntry;
}
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