How to extract best parameters from a CrossValidatorModel

Question

I want to find the parameters of ParamGridBuilder that make the best model in CrossValidator in Spark 1.4.x,

In Pipeline Example in Spark documentation,

Answer 1

To print everything in paramMap, you actually don't have to call parent:

cvModel.bestModel.extractParamMap()

To answer OP's question, to get a single best parameter, for example regParam:

cvModel.bestModel.extractParamMap().apply(cvModel.bestModel.getParam("regParam"))