IndexToString (IndexToString)

Java 类名：com.alibaba.alink.pipeline.dataproc.IndexToString

Python 类名：IndexToString

功能介绍

基于StringIndexer模型，将一列整数映射为字符串。

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
modelName	模型名字	模型名字	String	✓
selectedCol	选中的列名	计算列对应的列名	String	✓
modelFilePath	模型的文件路径	模型的文件路径	String			null
outputCol	输出结果列	输出结果列列名，可选，默认null	String			null
overwriteSink	是否覆写已有数据	是否覆写已有数据	Boolean			false
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
modelStreamFilePath	模型流的文件路径	模型流的文件路径	String			null
modelStreamScanInterval	扫描模型路径的时间间隔	描模型路径的时间间隔，单位秒	Integer			10
modelStreamStartTime	模型流的起始时间	模型流的起始时间。默认从当前时刻开始读。使用yyyy-mm-dd hh:mm:ss.fffffffff格式，详见Timestamp.valueOf(String s)	String			null

代码示例

Python 代码

from pyalink.alink import *

import pandas as pd

useLocalEnv(1)

df_data = pd.DataFrame([
    ["football"],
    ["football"],
    ["football"],
    ["basketball"],
    ["basketball"],
    ["tennis"],
])

train_data = BatchOperator.fromDataframe(df_data, schemaStr='f0 string')
data = StreamOperator.fromDataframe(df_data, schemaStr='f0 string')

stringIndexer = StringIndexer() \
    .setModelName("string_indexer_model") \
    .setSelectedCol("f0") \
    .setOutputCol("f0_indexed") \
    .setStringOrderType("frequency_asc").fit(train_data)

batch_model = stringIndexer.transform(train_data)
indexed = stringIndexer.transform(data)

indexToStrings = IndexToStringPredictStreamOp(batch_model) \
    .setSelectedCol("f0_indexed") \
    .setOutputCol("f0_indxed_unindexed")

indexToStrings.linkFrom(indexed).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.source.MemSourceBatchOp;
import com.alibaba.alink.operator.stream.StreamOperator;
import com.alibaba.alink.operator.stream.dataproc.IndexToStringPredictStreamOp;
import com.alibaba.alink.operator.stream.source.MemSourceStreamOp;
import com.alibaba.alink.pipeline.dataproc.StringIndexer;
import com.alibaba.alink.pipeline.dataproc.StringIndexerModel;
import org.junit.Test;

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

public class IndexToStringTest {
	@Test
	public void testIndexToString() throws Exception {
		List <Row> df_data = Arrays.asList(
			Row.of("football"),
			Row.of("football"),
			Row.of("football"),
			Row.of("basketball"),
			Row.of("basketball"),
			Row.of("tennis")
		);
		BatchOperator <?> train_data = new MemSourceBatchOp(df_data, "f0 string");
		StreamOperator <?> data = new MemSourceStreamOp(df_data, "f0 string");
		StringIndexerModel stringIndexer = new StringIndexer()
			.setModelName("string_indexer_model")
			.setSelectedCol("f0")
			.setOutputCol("f0_indexed")
			.setStringOrderType("frequency_asc").fit(train_data);
		BatchOperator batch_model = stringIndexer.transform(train_data);
		StreamOperator indexed = stringIndexer.transform(data);
		StreamOperator <?> indexToStrings = new IndexToStringPredictStreamOp(batch_model)
			.setSelectedCol("f0_indexed")
			.setOutputCol("f0_indxed_unindexed");
		indexToStrings.linkFrom(indexed).print();
		StreamOperator.execute();
	}
}

运行结果

f0	f0_indexed	f0_indxed_unindexed
football	2	football
football	2	football
football	2	football
basketball	1	basketball
basketball	1	basketball
tennis	0	tennis