[SPARK-1406] Added target field to the regression model for completeness

Adjusted unit test to deal with this change

Author: selvinsource

mllib/src/main/scala/org/apache/spark/mllib/export/pmml/GeneralizedLinearPMMLModelExport.scala

@@ -72,6 +72,16 @@ private[mllib] class GeneralizedLinearPMMLModelExport(
          regressionTable.withNumericPredictors(new NumericPredictor(fields(i), model.weights(i)))   
        }
 
+       //for completeness add target field
+       val targetField = FieldName.create("target");
+       dataDictionary
+        .withDataFields(
+            new DataField(targetField, OpType.CONTINUOUS, DataType.DOUBLE)
+        )
+        miningSchema
+         .withMiningFields(new MiningField(targetField)
+         .withUsageType(FieldUsageType.TARGET))
+       
        dataDictionary.withNumberOfFields((dataDictionary.getDataFields()).size())
 
        pmml.setDataDictionary(dataDictionary)

mllib/src/test/scala/org/apache/spark/mllib/export/pmml/GeneralizedLinearPMMLModelExportSuite.scala

@@ -45,7 +45,7 @@ class GeneralizedLinearPMMLModelExportSuite extends FunSuite{
     var pmml = linearModelExport.asInstanceOf[PMMLModelExport].getPmml()
     assert(pmml.getHeader().getDescription() === "linear regression")
     //check that the number of fields match the weights size
-    assert(pmml.getDataDictionary().getNumberOfFields() === linearRegressionModel.weights.size)
+    assert(pmml.getDataDictionary().getNumberOfFields() === linearRegressionModel.weights.size + 1)
     //this verify that there is a model attached to the pmml object and the model is a regression one
     //it also verifies that the pmml model has a regression table with the same number of predictors of the model weights
     assert(pmml.getModels().get(0).asInstanceOf[RegressionModel]
@@ -58,7 +58,7 @@ class GeneralizedLinearPMMLModelExportSuite extends FunSuite{
     pmml = ridgeModelExport.asInstanceOf[PMMLModelExport].getPmml()
     assert(pmml.getHeader().getDescription() === "ridge regression")
     //check that the number of fields match the weights size
-    assert(pmml.getDataDictionary().getNumberOfFields() === ridgeRegressionModel.weights.size)
+    assert(pmml.getDataDictionary().getNumberOfFields() === ridgeRegressionModel.weights.size + 1)
     //this verify that there is a model attached to the pmml object and the model is a regression one
     //it also verifies that the pmml model has a regression table with the same number of predictors of the model weights
     assert(pmml.getModels().get(0).asInstanceOf[RegressionModel]
@@ -71,7 +71,7 @@ class GeneralizedLinearPMMLModelExportSuite extends FunSuite{
     pmml = lassoModelExport.asInstanceOf[PMMLModelExport].getPmml()
     assert(pmml.getHeader().getDescription() === "lasso regression")
     //check that the number of fields match the weights size
-    assert(pmml.getDataDictionary().getNumberOfFields() === lassoModel.weights.size)
+    assert(pmml.getDataDictionary().getNumberOfFields() === lassoModel.weights.size + 1)
     //this verify that there is a model attached to the pmml object and the model is a regression one
     //it also verifies that the pmml model has a regression table with the same number of predictors of the model weights
     assert(pmml.getModels().get(0).asInstanceOf[RegressionModel]