title: How to plot velidation and training loss in same figure in Tensorboard
body: <p>I'm working with a Tensorflow object detection model with a config file similar to this <a href="https://github.com/tensorflow/models/blob/master/research/object_detection/samples/configs/faster_rcnn_inception_resnet_v2_atrous_coco.config" rel="nofollow noreferrer">tensorflow/research/object_detection/samples/configs/</a> file. However, when I plot the results in Tensorboard, I only see one graph for the loss/precision etc. I want to display both the training and validation loss in order to better evaluate the result, but I am relatively new to working with Tensorflow and thus need some guidance as to where/how this has to be written.</p>
  
  <p>I've looked into <a href="https://github.com/tensorflow/tensorboard/blob/master/tensorboard/plugins/custom_scalar/custom_scalar_demo.py" rel="nofollow noreferrer">tensorboard/tensorboard/plugins/custom_scalar/custom_scalar_demo.py</a> as well as <a href="https://stackoverflow.com/questions/37146614/tensorboard-plot-training-and-validation-losses-on-the-same-graph/37156491">this</a> stackoverflow post, however I am still a bit confused as to where this functionality should be written.</p>