BatchNormalization - 9 vs 15#

Next section compares an older to a newer version of the same operator after both definition are converted into markdown text. Green means an addition to the newer version, red means a deletion. Anything else is unchanged.

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  1. BatchNormalization9 → BatchNormalization15 +18 -62
BatchNormalization9 → BatchNormalization15 RENAMED
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  Carries out batch normalization as described in the paper
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  https://arxiv.org/abs/1502.03167. Depending on the mode it is being run,
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- There are five required inputs 'X', 'scale', 'B', 'input_mean' and
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- 'input_var'.
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- Note that 'input_mean' and 'input_var' are expected to be the estimated
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- statistics in inference mode (training_mode=False, default),
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- and the running statistics in training mode (training_mode=True).
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- There are multiple cases for the number of outputs, which we list below:
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+ there are multiple cases for the number of outputs, which we list below:
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+ Output case #1: Y, mean, var, saved_mean, saved_var (training mode)
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+ Output case #2: Y (test mode)
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- Output case #1: Y, running_mean, running_var (training_mode=True)
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- Output case #2: Y (training_mode=False)
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-
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- When training_mode=False, extra outputs are invalid.
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- The outputs are updated as follows when training_mode=True:
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- ::
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-
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- running_mean = input_mean * momentum + current_mean * (1 - momentum)
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- running_var = input_var * momentum + current_var * (1 - momentum)
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-
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- Y = (X - current_mean) / sqrt(current_var + epsilon) * scale + B
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-
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- where:
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-
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- current_mean = ReduceMean(X, axis=all_except_channel_index)
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- current_var = ReduceVar(X, axis=all_except_channel_index)
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-
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- Notice that ReduceVar refers to the population variance, and it equals to
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- sum(sqrd(x_i - x_avg)) / N
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- where N is the population size (this formula does not use sample size N - 1).
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-
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- The computation of ReduceMean and ReduceVar uses float to avoid overflow for float16 inputs.
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-
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- When training_mode=False:
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- ::
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-
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- Y = (X - input_mean) / sqrt(input_var + epsilon) * scale + B
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  For previous (depreciated) non-spatial cases, implementors are suggested
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- to flatten the input shape to (N x C * D1 * D2 * ... * Dn) before a BatchNormalization Op.
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+ to flatten the input shape to (N x C*D1*D2 ..*Dn) before a BatchNormalization Op.
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  This operator has **optional** inputs/outputs. See ONNX <https://github.com/onnx/onnx/blob/master/docs/IR.md>_ for more details about the representation of optional arguments. An empty string may be used in the place of an actual argument's name to indicate a missing argument. Trailing optional arguments (those not followed by an argument that is present) may also be simply omitted.
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  **Attributes**
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  * **epsilon**:
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  The epsilon value to use to avoid division by zero.
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  * **momentum**:
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  Factor used in computing the running mean and variance.e.g.,
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  running_mean = running_mean * momentum + mean * (1 - momentum).
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- * **training_mode**:
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- If set to true, it indicates BatchNormalization is being used for
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- training, and outputs 1, 2, 3, and 4 would be populated.
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  **Inputs**
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  * **X** (heterogeneous) - **T**:
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  Input data tensor from the previous operator; dimensions are in the
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  form of (N x C x D1 x D2 ... Dn), where N is the batch size, C is
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  the number of channels. Statistics are computed for every channel of
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  C over N and D1 to Dn dimensions. For image data, input dimensions
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  become (N x C x H x W). The op also accepts single dimension input
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  of size N in which case C is assumed to be 1
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- * **scale** (heterogeneous) - **T1**:
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+ * **scale** (heterogeneous) - **T**:
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  Scale tensor of shape (C).
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- * **B** (heterogeneous) - **T1**:
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+ * **B** (heterogeneous) - **T**:
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  Bias tensor of shape (C).
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- * **input_mean** (heterogeneous) - **T2**:
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+ * **mean** (heterogeneous) - **T**:
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  running (training) or estimated (testing) mean tensor of shape (C).
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- * **input_var** (heterogeneous) - **T2**:
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+ * **var** (heterogeneous) - **T**:
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  running (training) or estimated (testing) variance tensor of shape
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  (C).
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  **Outputs**
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- Between 1 and 3 outputs.
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+ Between 1 and 5 outputs.
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  * **Y** (heterogeneous) - **T**:
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  The output tensor of the same shape as X
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- * **running_mean** (optional, heterogeneous) - **T2**:
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+ * **mean** (optional, heterogeneous) - **T**:
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  The running mean after the BatchNormalization operator.
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- * **running_var** (optional, heterogeneous) - **T2**:
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+ * **var** (optional, heterogeneous) - **T**:
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- The running variance after the BatchNormalization operator. This op
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+ The running variance after the BatchNormalization operator.
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+ * **saved_mean** (optional, heterogeneous) - **T**:
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- uses the population size (N) for calculating variance, and not the
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+ Saved mean used during training to speed up gradient computation.
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+ * **saved_var** (optional, heterogeneous) - **T**:
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+ Saved variance used during training to speed up gradient
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- sample size N-1.
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+ computation.
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  **Type Constraints**
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  * **T** in (
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- tensor(bfloat16),
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  tensor(double),
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  tensor(float),
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  tensor(float16)
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  ):
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- Constrain input and output types to float tensors.
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+ Constrain input and output types to float tensors.- * **T1** in (
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- tensor(bfloat16),
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- tensor(double),
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- tensor(float),
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- tensor(float16)
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- ):
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- Constrain scale and bias types to float tensors.
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- * **T2** in (
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- tensor(bfloat16),
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- tensor(double),
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- tensor(float),
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- tensor(float16)
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- ):
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- Constrain mean and variance types to float tensors.