Java 类名：com.alibaba.alink.operator.batch.feature.ChiSqSelectorBatchOp
Python 类名：ChiSqSelectorBatchOp
功能介绍
针对table数据，进行特征筛选
参数说明
|
名称 |
中文名称 |
描述 |
类型 |
是否必须？ |
默认值 |
|
labelCol |
标签列名 |
输入表中的标签列名 |
String |
? |
|
|
selectedCols |
选择的列名 |
计算列对应的列名列表 |
String[] |
? |
|
|
selectorType |
筛选类型 |
筛选类型，包含"NumTopFeatures","percentile", "fpr", "fdr", "fwe"五种。 |
String |
"NumTopFeatures" |
|
|
numTopFeatures |
最大的p-value列个数 |
最大的p-value列个数, 默认值50 |
Integer |
50 |
|
|
percentile |
筛选的百分比 |
筛选的百分比，默认值0.1 |
Double |
0.1 |
|
|
fpr |
p value的阈值 |
p value的阈值，默认值0.05 |
Double |
0.05 |
|
|
fdr |
发现阈值 |
发现阈值, 默认值0.05 |
Double |
0.05 |
|
|
fwe |
错误率阈值 |
错误率阈值, 默认值0.05 |
Double |
0.05 |
代码示例
Python 代码
from pyalink.alink import * import pandas as pd useLocalEnv(1) df = pd.DataFrame([ ["a", 1, 1,2.0, True], ["c", 1, 2, -3.0, True], ["a", 2, 2,2.0, False], ["c", 0, 0, 0.0, False] ]) source = BatchOperator.fromDataframe(df, schemaStr=‘f_string string, f_long long, f_int int, f_double double, f_boolean boolean‘) selector = ChiSqSelectorBatchOp() .setSelectedCols(["f_string", "f_long", "f_int", "f_double"]) .setLabelCol("f_boolean") .setNumTopFeatures(2) selector.linkFrom(source) modelInfo: ChisqSelectorModelInfo = selector.collectModelInfo() print(modelInfo.getColNames())
Java 代码
import org.apache.flink.types.Row; import com.alibaba.alink.operator.batch.BatchOperator; import com.alibaba.alink.operator.batch.feature.ChiSqSelectorBatchOp; import com.alibaba.alink.operator.batch.source.MemSourceBatchOp; import com.alibaba.alink.operator.common.feature.ChisqSelectorModelInfo; import org.junit.Test; import java.util.Arrays; import java.util.List; public class ChiSqSelectorBatchOpTest { @Test public void testChiSqSelectorBatchOp() throws Exception { List <Row> df = Arrays.asList( Row.of("a", 1L, 1, 2.0, true), Row.of("c", 1L, 2, -3.0, true), Row.of("a", 2L, 2, 2.0, false), Row.of("c", 0L, 0, 0.0, false) ); BatchOperator <?> source = new MemSourceBatchOp(df, "f_string string, f_long long, f_int int, f_double double, f_boolean boolean"); ChiSqSelectorBatchOp selector = new ChiSqSelectorBatchOp() .setSelectedCols("f_string", "f_long", "f_int", "f_double") .setLabelCol("f_boolean") .setNumTopFeatures(2); selector.linkFrom(source); ChisqSelectorModelInfo modelInfo = selector.collectModelInfo(); System.out.println(modelInfo.toString()); } }
运行结果
------------------------- ChisqSelectorModelInfo ------------------------- Number of Selector Features: 2 Number of Features: 4 Type of Selector: NumTopFeatures Number of Top Features: 2 Selector Indices: | ColName|ChiSquare|PValue| DF|Selected| |--------|---------|------|---|--------| | f_long| 4|0.1353| 2| true| | f_int| 2|0.3679| 2| true| |f_double| 2|0.3679| 2| false| |f_string| 0| 1| 1| false|