message: Allow the Ftrl-proximal optimizer parameter 'initial_accumulator_value' to take zero values.
diff: @@ -53,7 +53,7 @@ class FtrlOptimizer(optimizer.Optimizer):
  learning_rate: A float value or a constant float `Tensor`.
  learning_rate_power: A float value, must be less or equal to zero.
  initial_accumulator_value: The starting value for accumulators.
  - Only positive values are allowed.
  + Only zero or positive values are allowed.
  l1_regularization_strength: A float value, must be greater than or
  equal to zero.
  l2_regularization_strength: A float value, must be greater than or
  @@ -84,8 +84,9 @@ class FtrlOptimizer(optimizer.Optimizer):
  """
  super(FtrlOptimizer, self).__init__(use_locking, name)
  - if initial_accumulator_value <= 0.0:
  - raise ValueError("initial_accumulator_value %f needs to be positive" %
  + if initial_accumulator_value < 0.0:
  + raise ValueError(
  + "initial_accumulator_value %f needs to be be positive or zero" %
  initial_accumulator_value)
  if learning_rate_power > 0.0:
  raise ValueError("learning_rate_power %f needs to be negative or zero" %
  