分桶 (BucketizerStreamOp)

Java 类名：com.alibaba.alink.operator.stream.feature.BucketizerStreamOp
Python 类名：BucketizerStreamOp

功能介绍

给定切分点，将连续变量分桶，需要选择需要进行切分的单列或多列，同时给出选中每列的切分点，每列切分点都是一个double数组，需要严格递增。

| 名称 | 中文名称 | 描述 | 类型 | 是否必须？ | 取值范围 | 默认值 | | —- | —- | —- | —- | —- | —- | —- |

| selectedCols | 选择的列名 | 计算列对应的列名列表 | String[] | ✓ | | |

| cutsArray | 多列的切分点 | 多列的切分点 | double[][] | | | |

| dropLast | 是否删除最后一个元素 | 删除最后一个元素是为了保证线性无关性。默认true | Boolean | | | true |

| encode | 编码方法 | 编码方法 | String | | “VECTOR”, “ASSEMBLED_VECTOR”, “INDEX” | “INDEX” |

| handleInvalid | 未知token处理策略 | 未知token处理策略。”keep”表示用最大id加1代替, “skip”表示补null， “error”表示抛异常 | String | | “KEEP”, “ERROR”, “SKIP” | “KEEP” |

| leftOpen | 是否左开右闭 | 左开右闭为true，左闭右开为false | Boolean | | | true |

| outputCols | 输出结果列列名数组 | 输出结果列列名数组，可选，默认null | String[] | | | null |

| reservedCols | 算法保留列名 | 算法保留列 | String[] | | | null |

| numThreads | 组件多线程线程个数 | 组件多线程线程个数 | Integer | | | 1 |

代码示例

Python 代码

from pyalink.alink import *
import pandas as pd
useLocalEnv(1)
df = pd.DataFrame([
    [1.1, True, "2", "A"],
    [1.1, False, "2", "B"],
    [1.1, True, "1", "B"],
    [2.2, True, "1", "A"]
])
inOp1 = BatchOperator.fromDataframe(df, schemaStr='double double, bool boolean, number int, str string')
inOp2 = StreamOperator.fromDataframe(df, schemaStr='double double, bool boolean, number int, str string')
bucketizer = BucketizerBatchOp().setSelectedCols(["double"]).setCutsArray([[2.0]])
bucketizer.linkFrom(inOp1).print()
bucketizer = BucketizerStreamOp().setSelectedCols(["double"]).setCutsArray([[2.0]])
bucketizer.linkFrom(inOp2).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.feature.BucketizerBatchOp;
import com.alibaba.alink.operator.batch.source.MemSourceBatchOp;
import com.alibaba.alink.operator.stream.StreamOperator;
import com.alibaba.alink.operator.stream.feature.BucketizerStreamOp;
import com.alibaba.alink.operator.stream.source.MemSourceStreamOp;
import org.junit.Test;
import java.util.Arrays;
import java.util.List;
public class BucketizerStreamOpTest {
    @Test
    public void testBucketizerStreamOp() throws Exception {
        List <Row> df = Arrays.asList(
            Row.of(1.1, true, 2, "A"),
            Row.of(1.1, false, 2, "B"),
            Row.of(1.1, true, 1, "B"),
            Row.of(2.2, true, 1, "A")
        );
        BatchOperator <?> inOp1 = new MemSourceBatchOp(df, "double double, bool boolean, number int, str string");
        StreamOperator <?> inOp2 = new MemSourceStreamOp(df, "double double, bool boolean, number int, str string");
        double[] cutsArr = {2.0};
        BatchOperator <?> bucketizer = new BucketizerBatchOp().setSelectedCols("double").setCutsArray(cutsArr);
        bucketizer.linkFrom(inOp1).print();
        StreamOperator <?> bucketizer2 = new BucketizerStreamOp().setSelectedCols("double").setCutsArray(cutsArr);
        bucketizer2.linkFrom(inOp2).print();
        StreamOperator.execute();
    }
}

运行结果

批预测结果

| double | bool | number | str | | —- | —- | —- | —- |

| 0 | true | 2 | A |

| 0 | false | 2 | B |

| 0 | true | 1 | B |

| 1 | true | 1 | A |

流预测结果

| double | bool | number | str | | —- | —- | —- | —- |

| 0 | true | 2 | A |

| 0 | true | 1 | B |

| 0 | false | 2 | B |

| 1 | true | 1 | A |