code: # Operations on a Computational Graph
  import matplotlib.pyplot as plt
  import numpy as np
  import tensorflow as tf
  from tensorflow.python.framework import ops
  ops.reset_default_graph()
  
  # Create graph
  sess = tf.Session()
  
  # Create tensors
  
  # Create data to feed in
  x_vals = np.array([1., 3., 5., 7., 9.])
  x_data = tf.placeholder(tf.float32)
  m = tf.constant(3.)
  
  # Multiplication
  prod = tf.mul(x_data, m)
  for x_val in x_vals:
      print(sess.run(prod, feed_dict={x_data: x_val}))
  
  merged = tf.merge_all_summaries()
  if not os.path.exists('tensorboard_logs/'):
      os.makedirs('tensorboard_logs/')
  
  my_writer = tf.train.SummaryWriter('tensorboard_logs/', sess.graph)
  
apis: tensorflow.placeholder tensorflow.train.SummaryWriter tensorflow.python.framework.ops.reset_default_graph tensorflow.mul tensorflow.Session numpy.array tensorflow.merge_all_summaries tensorflow.constant