ALINK(三十三)：特征工程（十二）特征组合与交叉（四）特征哈希 (FeatureHasherBatchOp)

import org.apache.flink.types.Row;
import com.alibaba.alink.operator.batch.BatchOperator;
import com.alibaba.alink.operator.batch.feature.FeatureHasherBatchOp;
import com.alibaba.alink.operator.batch.source.MemSourceBatchOp;
import com.alibaba.alink.operator.stream.StreamOperator;
import com.alibaba.alink.operator.stream.feature.FeatureHasherStreamOp;
import com.alibaba.alink.operator.stream.source.MemSourceStreamOp;
import org.junit.Test;
import java.util.Arrays;
import java.util.List;
public class FeatureHasherBatchOpTest {
  @Test
  public void testFeatureHasherBatchOp() 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");
    BatchOperator <?> hasher = new FeatureHasherBatchOp().setSelectedCols("double", "bool", "number", "str")
      .setOutputCol("output").setNumFeatures(200);
    hasher.linkFrom(inOp1).print();
    StreamOperator <?> hasher2 = new FeatureHasherStreamOp().setSelectedCols("double", "bool", "number", "str")
      .setOutputCol("output").setNumFeatures(200);
    hasher2.linkFrom(inOp2).print();
    StreamOperator.execute();
  }
}