code: # Copyright 2016 The TensorFlow Authors. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  # ==============================================================================
  """Tests for Python ops defined in nn_grad.py."""
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  import numpy as np
  
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.ops import gradient_checker
  from tensorflow.python.ops import gradients_impl
  from tensorflow.python.ops import nn_grad
  from tensorflow.python.ops import nn_ops
  from tensorflow.python.platform import test
  
  
  class Relu6OpTest(test.TestCase):
    def testRelu6GradGrad(self):
      inputs = constant_op.constant([[-2, -1, 1, 3], [5, 7, 8, 9]],
                                    dtype=dtypes.float32)
      x_init_value = np.array([[-3.5, -1.5, 2, 4], [4.5, 7.5, 8.5, 11]])
      r = nn_ops.relu6(inputs)
      r_g = gradients_impl.gradients(r, inputs)[0]
      with self.test_session():
        error = gradient_checker.compute_gradient_error(
          inputs, inputs.get_shape().as_list(),
          r_g, r_g.get_shape().as_list(),
          x_init_value=x_init_value)
        self.assertLess(error, 1e-4)
  
  
  if __name__ == "__main__":
    test.main()
  
apis: tensorflow.python.ops.nn_ops.relu6 tensorflow.python.ops.gradients_impl.gradients tensorflow.python.platform.test.main numpy.array tensorflow.python.framework.constant_op.constant