决策树训练 (DecisionTreeTrainBatchOp)

Java 类名:com.alibaba.alink.operator.batch.classification.DecisionTreeTrainBatchOp

Python 类名:DecisionTreeTrainBatchOp

功能介绍

  • 决策树组件支持稠密数据格式

  • 支持带样本权重的训练

参数说明

名称 中文名称 描述 类型 是否必须? 取值范围 默认值
labelCol 标签列名 输入表中的标签列名 String
categoricalCols 离散特征列名 离散特征列名 String[] 所选列类型为 [BOOLEAN, DATE, DOUBLE, FLOAT, INTEGER, LONG, SHORT, STRING, TIME, TIMESTAMP]
createTreeMode 创建树的模式。 series表示每个单机创建单颗树,parallel表示并行创建单颗树。 String “series”
featureCols 特征列名数组 特征列名数组,默认全选 String[] 所选列类型为 [BOOLEAN, DATE, DOUBLE, FLOAT, INTEGER, LONG, SHORT, STRING, TIME, TIMESTAMP] null
maxBins 连续特征进行分箱的最大个数 连续特征进行分箱的最大个数。 Integer 128
maxDepth 树的深度限制 树的深度限制 Integer 2147483647
maxLeaves 叶节点的最多个数 叶节点的最多个数 Integer 2147483647
maxMemoryInMB 树模型中用来加和统计量的最大内存使用数 树模型中用来加和统计量的最大内存使用数 Integer 64
minInfoGain 分裂的最小增益 分裂的最小增益 Double 0.0
minSampleRatioPerChild 子节点占父节点的最小样本比例 子节点占父节点的最小样本比例 Double 0.0
minSamplesPerLeaf 叶节点的最小样本个数 叶节点的最小样本个数 Integer 2
treeType 模型中树的类型 模型中树的类型,三种选项可选:树为一种方式gini, infoGain, infoGainRatio String “GINI”, “INFOGAIN”, “INFOGAINRATIO” “GINI”
weightCol 权重列名 权重列对应的列名 String 所选列类型为 [BIGDECIMAL, BIGINTEGER, BYTE, DOUBLE, FLOAT, INTEGER, LONG, SHORT] null

代码示例

Python 代码

from pyalink.alink import *

import pandas as pd

useLocalEnv(1)

df = pd.DataFrame([
    [1.0, "A", 0, 0, 0],
    [2.0, "B", 1, 1, 0],
    [3.0, "C", 2, 2, 1],
    [4.0, "D", 3, 3, 1]
])
batchSource = BatchOperator.fromDataframe(
    df, schemaStr=' f0 double, f1 string, f2 int, f3 int, label int')
streamSource = StreamOperator.fromDataframe(
    df, schemaStr=' f0 double, f1 string, f2 int, f3 int, label int')

trainOp = DecisionTreeTrainBatchOp()\
    .setLabelCol('label')\
    .setFeatureCols(['f0', 'f1', 'f2', 'f3'])\
    .linkFrom(batchSource)
predictBatchOp = DecisionTreePredictBatchOp()\
    .setPredictionDetailCol('pred_detail')\
    .setPredictionCol('pred')
predictStreamOp = DecisionTreePredictStreamOp(trainOp)\
    .setPredictionDetailCol('pred_detail')\
    .setPredictionCol('pred')

predictBatchOp.linkFrom(trainOp, batchSource).print()
predictStreamOp.linkFrom(streamSource).print()

StreamOperator.execute()

Java 代码

import org.apache.flink.types.Row;

import com.alibaba.alink.operator.batch.BatchOperator;
import com.alibaba.alink.operator.batch.classification.DecisionTreePredictBatchOp;
import com.alibaba.alink.operator.batch.classification.DecisionTreeTrainBatchOp;
import com.alibaba.alink.operator.batch.source.MemSourceBatchOp;
import com.alibaba.alink.operator.stream.StreamOperator;
import com.alibaba.alink.operator.stream.classification.DecisionTreePredictStreamOp;
import com.alibaba.alink.operator.stream.source.MemSourceStreamOp;
import org.junit.Test;

import java.util.Arrays;
import java.util.List;

public class DecisionTreeTrainBatchOpTest {
	@Test
	public void testDecisionTreeTrainBatchOp() throws Exception {
		List <Row> df = Arrays.asList(
			Row.of(1.0, "A", 0, 0, 0),
			Row.of(2.0, "B", 1, 1, 0),
			Row.of(3.0, "C", 2, 2, 1),
			Row.of(4.0, "D", 3, 3, 1)
		);

		BatchOperator <?> batchSource = new MemSourceBatchOp(
			df, " f0 double, f1 string, f2 int, f3 int, label int");
		StreamOperator <?> streamSource = new MemSourceStreamOp(
			df, " f0 double, f1 string, f2 int, f3 int, label int");
		BatchOperator <?> trainOp = new DecisionTreeTrainBatchOp()
			.setLabelCol("label")
			.setFeatureCols("f0", "f1", "f2", "f3")
			.linkFrom(batchSource);
		BatchOperator <?> predictBatchOp = new DecisionTreePredictBatchOp()
			.setPredictionDetailCol("pred_detail")
			.setPredictionCol("pred");
		StreamOperator <?> predictStreamOp = new DecisionTreePredictStreamOp(trainOp)
			.setPredictionDetailCol("pred_detail")
			.setPredictionCol("pred");
		predictBatchOp.linkFrom(trainOp, batchSource).print();
		predictStreamOp.linkFrom(streamSource).print();
		StreamOperator.execute();
	}
}

运行结果

f0 f1 f2 f3 label pred pred_detail
1.0000 A 0 0 0 0 {“0”:1.0,“1”:0.0}
2.0000 B 1 1 0 0 {“0”:1.0,“1”:0.0}
3.0000 C 2 2 1 1 {“0”:0.0,“1”:1.0}
4.0000 D 3 3 1 1 {“0”:0.0,“1”:1.0}