Java 类名:com.alibaba.alink.pipeline.regression.AftSurvivalRegression
Python 类名:AftSurvivalRegression
功能介绍
在生存分析领域,加速失效时间模型(accelerated failure time model,AFT 模型)可以作为比例风险模型的替代模型。生存回归组件支持稀疏、稠密两种数据格式。
算法原理
AFT模型将线性回归模型的建模方法引人到生存分析的领域, 将生存时间的对数作为反应变量,研究多协变量与对数生存时间之间的回归关系,在形式上,模型与一般的线性回归模型相似。对回归系数的解释也与一般的线性回归模型相似,较之Cox模型, AFT模型对分析结果的解释更加简单、直观且易于理解,并且可以预测个体的生存时间。
算法使用
生存回归分析是研究特定事件的发生与时间的关系的回归。这里特定事件可以是:病人死亡、病人康复、用户流失、商品下架等。
- 备注 :该组件训练的时候 FeatureCols 和 VectorCol 是两个互斥参数,只能有一个参数来描述算法的输入特征。
文献或出处
[1] Wei, Lee-Jen. “The accelerated failure time model: a useful alternative to the Cox regression model in survival analysis.” Statistics in medicine 11.14‐15 (1992): 1871-1879.
[2] https://spark.apache.org/docs/latest/ml-classification-regression.html#survival-regression
名称 | 中文名称 | 描述 | 类型 | 是否必须? | 取值范围 | 默认值 |
---|---|---|---|---|---|---|
censorCol | 生存列名 | 生存列名 | String | ✓ | ||
labelCol | 标签列名 | 输入表中的标签列名 | String | ✓ | ||
predictionCol | 预测结果列名 | 预测结果列名 | String | ✓ | ||
epsilon | 收敛阈值 | 迭代方法的终止判断阈值,默认值为 1.0e-6 | Double | [0.0, +inf) | 1.0E-6 | |
featureCols | 特征列名数组 | 特征列名数组,默认全选 | String[] | null | ||
l1 | L1 正则化系数 | L1 正则化系数,默认为0。 | Double | [0.0, +inf) | 0.0 | |
l2 | 正则化系数 | L2 正则化系数,默认为0。 | Double | [0.0, +inf) | 0.0 | |
maxIter | 最大迭代步数 | 最大迭代步数,默认为 100 | Integer | [1, +inf) | 100 | |
modelFilePath | 模型的文件路径 | 模型的文件路径 | String | null | ||
overwriteSink | 是否覆写已有数据 | 是否覆写已有数据 | Boolean | false | ||
predictionDetailCol | 预测详细信息列名 | 预测详细信息列名 | String | |||
quantileProbabilities | 分位数概率数组 | 分位数概率数组 | double[] | [0.01,0.05,0.1,0.25,0.5,0.75,0.9,0.95,0.99] | ||
reservedCols | 算法保留列名 | 算法保留列 | String[] | null | ||
vectorCol | 向量列名 | 向量列对应的列名,默认值是null | String | null | ||
withIntercept | 是否有常数项 | 是否有常数项,默认true | Boolean | true | ||
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 = pd.DataFrame([
[1.218, 1.0, "1.560,-0.605"],
[2.949, 0.0, "0.346,2.158"],
[3.627, 0.0, "1.380,0.231"],
[0.273, 1.0, "0.520,1.151"],
[4.199, 0.0, "0.795,-0.226"]])
data = BatchOperator.fromDataframe(df, schemaStr="label double, censor double, features string")
reg = AftSurvivalRegression()\
.setVectorCol("features")\
.setLabelCol("label")\
.setCensorCol("censor")\
.setPredictionCol("result")
pipeline = Pipeline().add(reg)
model = pipeline.fit(data)
model.save().lazyPrint(10)
model.transform(data).print()
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.pipeline.Pipeline;
import com.alibaba.alink.pipeline.PipelineModel;
import com.alibaba.alink.pipeline.regression.AftSurvivalRegression;
import org.junit.Test;
import java.util.Arrays;
import java.util.List;
public class AftSurvivalRegressionTest {
@Test
public void testAftSurvivalRegression() throws Exception {
List <Row> df = Arrays.asList(
Row.of(1.218, 1.0, "1.560,-0.605"),
Row.of(2.949, 0.0, "0.346,2.158"),
Row.of(3.627, 0.0, "1.380,0.231"),
Row.of(0.273, 1.0, "0.520,1.151")
);
BatchOperator <?> data = new MemSourceBatchOp(df, "label double, censor double, features string");
AftSurvivalRegression reg = new AftSurvivalRegression()
.setVectorCol("features")
.setLabelCol("label")
.setCensorCol("censor")
.setPredictionCol("result");
Pipeline pipeline = new Pipeline().add(reg);
PipelineModel model = pipeline.fit(data);
model.save().lazyPrint(10);
model.transform(data).print();
}
}
运行结果
模型
| id | p0 | p1 | p2 | | —- | —- | —- | —- |
| -1 | {“stages”:”[{“identifier”:null,”params”:null,”schemaIndices”:[1,0,2],”colNames”:null,”parent”:-1},{“identifier”:”com.alibaba.alink.pipeline.regression.AftSurvivalRegressionModel”,”params”:{“params”:{“vectorCol”:”\“features\“”,”labelCol”:”\“label\“”,”censorCol”:”\“censor\“”,”predictionCol”:”\“result\“”}},”schemaIndices”:[1,0,2],”colNames”:[“model_id”,”model_info”,”label_value”],”parent”:0}]”} | null | null |
| 1 | {“hasInterceptItem”:”true”,”vectorCol”:””features””,”modelName”:””AFTSurvivalRegTrainBatchOp””,”labelCol”:””label””,”linearModelType”:””AFT””,”vectorSize”:”3”} | 0 | null |
| 1 | {“featureColNames”:null,”featureColTypes”:null,”coefVector”:{“data”:[-29.487324590178716,24.42773010344541,13.44725070039797,-1.3679961023031253]},”coefVectors”:null,”convergenceInfo”:[1.5843984652595493,3.6032723097911044,0.4,1.4794299745122195,0.9580954096270979,1.6,1.3777797119903465,0.7050802052575507,1.6,1.3399286821587995,0.3682693394041936,1.6,1.312648708021441,0.24739884143507995,4.0,1.2685626011340911,0.18750659133206055,4.0,1.253583736945237,0.14860925947925266,4.0,1.2281061305710799,0.14586073980515185,4.0,1.0942468743404496,0.18594588792948594,4.0,0.8350708072737613,0.3504767418363587,4.0,0.8350708072737618,0.5905879812330285,0.25,0.5762249843357561,0.5905879812330285,0.25,0.5161276782605526,0.7008299684632876,0.25,0.3872690319921853,0.6482128538375713,1.0,0.3872690319921861,0.6448719615922804,0.0625,0.3786668764217095,0.6448719615922804,0.0625,0.3354192551580446,3.6845873037311816,0.25,0.26183684259256024,3.141816288006177,1.0,-0.07097230167077419,2.6843478562459735,1.0]} | 1048576 | null |
结果
| label | censor | features | result | | —- | —- | —- | —- |
| 1.2180 | 1.0000 | 1.560,-0.605 | 1.6231 |
| 2.9490 | 0.0000 | 0.346,2.158 | 2933.1642 |
| 3.6270 | 0.0000 | 1.380,0.231 | 1524.2502 |
| 0.2730 | 1.0000 | 0.520,1.151 | 0.2706 |