CLN: replace safe_div method by div_no_nan

tensorflow/contrib/losses/python/losses/loss_ops.py

@@ -66,32 +66,6 @@ def _scale_losses(losses, weights):
   return math_ops.reduce_sum(reduced_losses)
 
 
-def _safe_div(numerator, denominator, name="value"):
-  """Computes a safe divide which returns 0 if the denominator is zero.
-
-  Note that the function contains an additional conditional check that is
-  necessary for avoiding situations where the loss is zero causing NaNs to
-  creep into the gradient computation.
-
-  Args:
-    numerator: An arbitrary `Tensor`.
-    denominator: A `Tensor` whose shape matches `numerator` and whose values are
-      assumed to be non-negative.
-    name: An optional name for the returned op.
-
-  Returns:
-    The element-wise value of the numerator divided by the denominator.
-  """
-  return array_ops.where(
-      math_ops.greater(denominator, 0),
-      math_ops.div(numerator,
-                   array_ops.where(
-                       math_ops.equal(denominator, 0),
-                       array_ops.ones_like(denominator), denominator)),
-      array_ops.zeros_like(numerator),
-      name=name)
-
-
 def _safe_mean(losses, num_present):
   """Computes a safe mean of the losses.
 
@@ -104,7 +78,8 @@ def _safe_mean(losses, num_present):
       then zero is returned.
   """
   total_loss = math_ops.reduce_sum(losses)
-  return _safe_div(total_loss, num_present)
+  return math_ops.div_no_nan(total_loss, num_present,
+                             negative_to_zero=True, name="value")
 
 
 @deprecated("2016-12-30", "Use tf.losses.compute_weighted_loss instead.")
@@ -609,11 +584,16 @@ def mean_pairwise_squared_error(predictions,
         math_ops.square(diffs), reduction_indices=reduction_indices)
     num_present_per_batch = _num_present(diffs, weights, per_batch=True)
 
-    term1 = 2.0 * _safe_div(sum_squares_diff_per_batch, num_present_per_batch)
+    term1 = 2.0 * math_ops.div_no_nan(sum_squares_diff_per_batch,
+                                      num_present_per_batch,
+                                      negative_to_zero=True,
+                                      name="value")
 
     sum_diff = math_ops.reduce_sum(diffs, reduction_indices=reduction_indices)
-    term2 = 2.0 * _safe_div(
-        math_ops.square(sum_diff), math_ops.square(num_present_per_batch))
+    term2 = 2.0 * math_ops.div_no_nan(math_ops.square(sum_diff),
+                                      math_ops.square(num_present_per_batch),
+                                      negative_to_zero=True,
+                                      name="value")
 
     loss = _scale_losses(term1 - term2, weights)
 

tensorflow/contrib/metrics/python/ops/metric_ops.py

@@ -45,24 +45,6 @@
 _EPSILON = 1e-7
 
 
-def _safe_div(numerator, denominator, name):
-  """Divides two values, returning 0 if the denominator is <= 0.
-
-  Args:
-    numerator: A real `Tensor`.
-    denominator: A real `Tensor`, with dtype matching `numerator`.
-    name: Name for the returned op.
-
-  Returns:
-    0 if `denominator` <= 0, else `numerator` / `denominator`
-  """
-  return array_ops.where(
-      math_ops.greater(denominator, 0),
-      math_ops.truediv(numerator, denominator),
-      0,
-      name=name)
-
-
 @deprecated(None, 'Please switch to tf.metrics.true_positives. Note that the '
             'order of the labels and predictions arguments has been switched.')
 def streaming_true_positives(predictions,
@@ -3205,22 +3187,28 @@ def streaming_covariance(predictions,
 
     # We update the means by Delta=Error*BatchCount/(BatchCount+PrevCount)
     # batch_mean_prediction is E[x_B] in the update equation
-    batch_mean_prediction = _safe_div(
+    batch_mean_prediction = math_ops.div_no_nan(
         math_ops.reduce_sum(weighted_predictions), batch_count,
-        'batch_mean_prediction')
-    delta_mean_prediction = _safe_div(
+        negative_to_zero=True,
+        name='batch_mean_prediction')
+    delta_mean_prediction = math_ops.div_no_nan(
         (batch_mean_prediction - mean_prediction) * batch_count, update_count,
-        'delta_mean_prediction')
+        negative_to_zero=True,
+        name='delta_mean_prediction')
     update_mean_prediction = state_ops.assign_add(mean_prediction,
                                                   delta_mean_prediction)
     # prev_mean_prediction is E[x_A] in the update equation
     prev_mean_prediction = update_mean_prediction - delta_mean_prediction
 
     # batch_mean_label is E[y_B] in the update equation
-    batch_mean_label = _safe_div(
-        math_ops.reduce_sum(weighted_labels), batch_count, 'batch_mean_label')
-    delta_mean_label = _safe_div((batch_mean_label - mean_label) * batch_count,
-                                 update_count, 'delta_mean_label')
+    batch_mean_label = math_ops.div_no_nan(
+        math_ops.reduce_sum(weighted_labels), batch_count,
+        negative_to_zero=True,
+        name='batch_mean_label')
+    delta_mean_label = math_ops.div_no_nan(
+        (batch_mean_label - mean_label) * batch_count, update_count,
+        negative_to_zero=True,
+        name='delta_mean_label')
     update_mean_label = state_ops.assign_add(mean_label, delta_mean_label)
     # prev_mean_label is E[y_A] in the update equation
     prev_mean_label = update_mean_label - delta_mean_label
@@ -3882,8 +3870,10 @@ def _calculate_k(po, pe_row, pe_col, name):
       po_sum = math_ops.reduce_sum(po)
       total = math_ops.reduce_sum(pe_row)
       pe_sum = math_ops.reduce_sum(
-          metrics_impl._safe_div(  # pylint: disable=protected-access
-              pe_row * pe_col, total, None))
+          math_ops.div_no_nan(
+              pe_row * pe_col, total,
+              negative_to_zero=True,
+              name=None))
       po_sum, pe_sum, total = (math_ops.to_double(po_sum),
                                math_ops.to_double(pe_sum),
                                math_ops.to_double(total))

tensorflow/contrib/rate/rate.py

@@ -108,13 +108,6 @@ def name(self):
   def variables(self):
     return self._vars
 
-  def _safe_div(self, numerator, denominator, name):
-    t = math_ops.truediv(numerator, denominator)
-    zero = array_ops.zeros_like(t, dtype=denominator.dtype)
-    condition = math_ops.greater(denominator, zero)
-    zero = math_ops.cast(zero, t.dtype)
-    return array_ops.where(condition, t, zero, name=name)
-
   def _add_variable(self, name, shape=None, dtype=None):
     """Private method for adding variables to the graph."""
     if self._built:
@@ -148,4 +141,6 @@ def call(self, values, denominator):
     state_ops.assign(self.prev_values, values)
     state_ops.assign(self.prev_denominator, denominator)
 
-    return self._safe_div(self.numer, self.denom, name="safe_rate")
+    return math_ops.div_no_nan(self.numer, self.denom,
+                               negative_to_zero=True,
+                               name="safe_rate")

tensorflow/python/keras/engine/training_utils.py

@@ -607,7 +607,8 @@ def weighted(y_true, y_pred, weights, mask=None):
       score_array = math_ops.multiply(score_array, weights)
       score_array = math_ops.reduce_sum(score_array)
       weights = math_ops.reduce_sum(weights)
-      score_array = metrics_module.safe_div(score_array, weights)
+      score_array = math_ops.div_no_nan(score_array, weights,
+                                        negative_to_zero=True)
     return K.mean(score_array)
 
   return weighted

tensorflow/python/keras/metrics.py

@@ -136,23 +136,6 @@ def merge_fn_wrapper(distribution, merge_fn, *args):
   return tf_decorator.make_decorator(result_fn, decorated)
 
 
-def safe_div(numerator, denominator):
-  """Divides two tensors element-wise, returning 0 if the denominator is <= 0.
-
-  Args:
-    numerator: A `Tensor`.
-    denominator: A `Tensor`, with dtype matching `numerator`.
-
-  Returns:
-    0 if `denominator` <= 0, else `numerator` / `denominator`
-  """
-  t = math_ops.truediv(numerator, denominator)
-  zero = array_ops.zeros_like(t, dtype=denominator.dtype)
-  condition = math_ops.greater(denominator, zero)
-  zero = math_ops.cast(zero, t.dtype)
-  return array_ops.where(condition, t, zero)
-
-
 def squeeze_or_expand_dimensions(y_pred, y_true, sample_weight):
   """Squeeze or expand last dimension if needed.
 
@@ -472,7 +455,7 @@ def update_state(self, values, sample_weight=None):
     state_ops.assign_add(self.count, num_values)
 
   def result(self):
-    return safe_div(self.total, self.count)
+    return math_ops.div_no_nan(self.total, self.count, negative_to_zero=True)
 
 
 class MeanMetricWrapper(Mean):

tensorflow/python/kernel_tests/losses_test.py

@@ -34,25 +34,11 @@
 from tensorflow.python.ops import variable_scope
 from tensorflow.python.ops import variables
 from tensorflow.python.ops.losses import losses
-from tensorflow.python.ops.losses import losses_impl
 from tensorflow.python.ops.losses import util
 from tensorflow.python.platform import test
 from tensorflow.python.training import momentum as momentum_lib
 
 
-safe_div = losses_impl._safe_div  # pylint: disable=protected-access
-
-
-class SafeDivTest(test.TestCase):
-
-  def testEager(self):
-    with context.eager_mode():
-      self.assertAllEqual(safe_div(constant_op.constant(1.0),
-                                   constant_op.constant(0.0)), 0.0)
-      self.assertAllEqual(safe_div(constant_op.constant(1.0),
-                                   0.0), 0.0)
-
-
 class AbsoluteDifferenceLossTest(test.TestCase):
 
   def setUp(self):

tensorflow/python/ops/losses/losses_impl.py

@@ -74,31 +74,6 @@ def validate(cls, key):
       raise ValueError("Invalid ReductionKey %s." % key)
 
 
-def _safe_div(numerator, denominator, name="value"):
-  """Computes a safe divide which returns 0 if the denominator is zero.
-
-  Note that the function contains an additional conditional check that is
-  necessary for avoiding situations where the loss is zero causing NaNs to
-  creep into the gradient computation.
-
-  Args:
-    numerator: An arbitrary `Tensor`.
-    denominator: `Tensor` whose shape matches `numerator` and whose values are
-      assumed to be non-negative.
-    name: An optional name for the returned op.
-
-  Returns:
-    The element-wise value of the numerator divided by the denominator.
-  """
-  return array_ops.where(
-      math_ops.greater(denominator, 0),
-      math_ops.div(numerator, array_ops.where(
-          math_ops.equal(denominator, 0),
-          array_ops.ones_like(denominator), denominator)),
-      array_ops.zeros_like(numerator),
-      name=name)
-
-
 def _safe_mean(losses, num_present):
   """Computes a safe mean of the losses.
 
@@ -111,7 +86,8 @@ def _safe_mean(losses, num_present):
       then zero is returned.
   """
   total_loss = math_ops.reduce_sum(losses)
-  return _safe_div(total_loss, num_present)
+  return math_ops.div_no_nan(total_loss, num_present,
+                             negative_to_zero=True, name="value")
 
 
 def _num_present(losses, weights, per_batch=False):
@@ -599,14 +575,18 @@ def mean_pairwise_squared_error(
           keepdims=True)
       num_present_per_batch = _num_present(diffs, weights, per_batch=True)
 
-      term1 = 2.0 * _safe_div(sum_squares_diff_per_batch,
-                              num_present_per_batch - 1)
+      term1 = 2.0 * math_ops.div_no_nan(sum_squares_diff_per_batch,
+                                        num_present_per_batch - 1,
+                                        negative_to_zero=True,
+                                        name="value")
 
       sum_diff = math_ops.reduce_sum(
           diffs, reduction_indices=reduction_indices, keepdims=True)
-      term2 = 2.0 * _safe_div(
+      term2 = 2.0 * math_ops.div_no_nan(
           math_ops.square(sum_diff),
-          math_ops.multiply(num_present_per_batch, num_present_per_batch - 1))
+          math_ops.multiply(num_present_per_batch, num_present_per_batch - 1),
+          negative_to_zero=True,
+          name="value")
 
       weighted_losses = math_ops.multiply(term1 - term2, weights)
       loss = math_ops.reduce_sum(weighted_losses)