class_docstr: Estimator class for training and evaluation BigDL models.
  
  Estimator wraps a model, and provide an uniform training, evaluation or prediction operation on
  both local host and distributed spark environment.
class_docstr_tok: ["Estimator","class","for","training","and","evaluation","BigDL","models",".","Estimator","wraps","a","model",",","and","provide","an","uniform","training",",","evaluation","or","prediction","operation","on","both","local","host","and","distributed","spark","environment","."]
docstr: Get the scalar from model train summary
  Return 2-D array like object which could be converted
  by nd.array()
  # Arguments
  tag: The string variable represents the scalar wanted
docstr_tok: ["Get","the","scalar","from","model","train","summary","Return","2-D","array","like","object","which","could","be","converted","by","nd.array","(",")","#","Arguments","tag",":","The","string","variable","represents","the","scalar","wanted"]
code: def get_train_summary(self, tag=None):
      """
      Get the scalar from model train summary
      Return 2-D array like object which could be converted
      by nd.array()
      # Arguments
      tag: The string variable represents the scalar wanted
      """
      # exception handle
      if (
          tag != "Loss"
          and tag != "LearningRate"
          and tag != "Throughput"
      ):
          invalidInputError(
              False,
              'Only "Loss", "LearningRate", "Throughput"'
              + "are supported in train summary",
          )
  
      return callZooFunc(
          "float",
          "estimatorGetScalarFromSummary",
          self.value,
          tag,
          "Train",
      )
  
file_path: BigDL/python/dllib/src/bigdl/dllib/estimator/estimator.py
imports: from bigdl.dllib.utils.common import JavaValue
  from bigdl.dllib.utils.file_utils import callZooFunc
  from bigdl.dllib.utils.log4Error import *
label_desc: Use image node_id 6 for calling the Estimator obj's underlying member method code with example usage: obj.get_train_summary(tag) and returns: callZooFunc