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"
      ):
          raise TypeError(
              'Only "Loss", "LearningRate", "Throughput"'
              + "are supported in train summary"
          )
  
      return callZooFunc(
          self.bigdl_type,
          "zooGetScalarFromSummary",
          self.value,
          tag,
          "Train",
      )
  
imports: import zoo.pipeline.api.autograd
  from zoo.feature.image import ImageSet
  from zoo.feature.text import TextSet
  from zoo.feature.common import FeatureSet
  from zoo.pipeline.api.keras.base import ZooKerasLayer
  from zoo.pipeline.api.keras.utils import *
  from bigdl.nn.layer import Layer
  from zoo.common.utils import callZooFunc
label_desc: Use image node_id 5 for calling the KerasNet obj's underlying member method code with example usage: obj.get_train_summary(tag) and returns: callZooFunc