Github user WeichenXu123 commented on the issue:
https://github.com/apache/spark/pull/19208
I manually tested backwards compatibility and it works fine. I paste the
test code for `CrossValidator` here.
Run following code in spark-2.2 shell first:
```
import java.io.File
import org.apache.spark.ml.tuning._
import org.apache.spark.ml.{Estimator, Model, Pipeline}
import org.apache.spark.ml.classification.{LogisticRegression,
LogisticRegressionModel, OneVsRest}
import org.apache.spark.ml.feature.HashingTF
import org.apache.spark.ml.linalg.Vectors
import org.apache.spark.ml.param.ParamMap
import org.apache.spark.ml.regression.LinearRegression
import org.apache.spark.sql.Dataset
import org.apache.spark.sql.types.StructType
import org.apache.spark.ml.evaluation.{BinaryClassificationEvaluator,
Evaluator, MulticlassClassificationEvaluator, RegressionEvaluator}
import org.apache.spark.ml.feature.{Instance, LabeledPoint}
def generateLogisticInput(offset: Double,scale: Double,nPoints: Int,seed:
Int):Seq[LabeledPoint] = {
val rnd = new java.util.Random(seed)
val x1 = Array.fill[Double](nPoints)(rnd.nextGaussian())
val y = (0 until nPoints).map { i =>
val p = 1.0 / (1.0 + math.exp(-(offset + scale * x1(i))))
if (rnd.nextDouble() < p) 1.0 else 0.0
}
val testData = (0 until nPoints).map(i => LabeledPoint(y(i),
Vectors.dense(Array(x1(i)))))
testData
}
import spark.implicits._
val dataset = sc.parallelize(generateLogisticInput(0.0, 1.0, 10, 42),
2).toDF()
val lr = new LogisticRegression
val lrParamMaps = new ParamGridBuilder().addGrid(lr.regParam, Array(0.001,
1000.0)).addGrid(lr.maxIter, Array(0, 3)).build()
val eval = new BinaryClassificationEvaluator
val numFolds = 3
val cv = new
CrossValidator().setEstimator(lr).setEstimatorParamMaps(lrParamMaps).setEvaluator(eval).setNumFolds(numFolds)
val cvModel = cv.fit(dataset)
cvModel.save("file:///Users/weichenxu/work/test/s1")
```
and then run following code on current PR: (in spark-shell)
```
val model =
org.apache.spark.ml.tuning.CrossValidatorModel.load("file:///Users/weichenxu/work/test/s1")
model.hasSubModels
```
---
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
