BatchNormalization - 6 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Next section compares an older to a newer version of the same operator after both definition are converted into markdown text.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. BatchNormalization6 → BatchNormalization15 +46 -80
BatchNormalization6 → 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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-
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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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- 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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+ The epsilon value to use to avoid division by zero, default is
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+ 1e-5f.
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+ * **is_test**:
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+ If set to nonzero, run spatial batch normalization in test mode,
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+ default is 0.
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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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+ running_mean = running_mean * momentum + mean * (1 - momentum),
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+ default is 0.9f.
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- * **training_mode**:
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+ * **spatial**:
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- If set to true, it indicates BatchNormalization is being used for
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+ If true, compute the mean and variance across all spatial elements
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- training, and outputs 1, 2, 3, and 4 would be populated.
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+ If false, compute the mean and variance across per feature.Default
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+ is 1.
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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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+ Input data tensor from the previous operator; dimensions for image
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+ case are (N x C x H x W), where N is the batch size, C is the number
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+ of channels, and H and W are the height and the width of the data.
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+ For non image case, the dimensions are in the form of (N x C x D1 x
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+ D2 ... Dn), where N is the batch size.
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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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+ The scale as a 1-dimensional tensor of size C to be applied to the
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+ output.
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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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+ The bias as a 1-dimensional tensor of size C to be applied to the
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+ output.
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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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+ The running mean (training) or the estimated mean (testing) as a
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+ 1-dimensional tensor of size 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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+ The running variance (training) or the estimated variance (testing)
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- (C).
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+ as a 1-dimensional tensor of size 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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+ 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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+ The running mean after the BatchNormalization operator. Must be in-
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+ place with the input mean. Should not be used for testing.
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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. Must be
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- uses the population size (N) for calculating variance, and not the
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+ in-place with the input var. Should not be used for testing.
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+ * **saved_mean** (optional, heterogeneous) - **T**:
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+ Saved mean used during training to speed up gradient computation.
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- sample size N-1.
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+ Should not be used for testing.
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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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+ computation. Should not be used for testing.
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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.