tf.clip_by_norm

TensorFlow 1 version

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Clips tensor values to a maximum L2-norm.

tf.clip_by_norm(
    t, clip_norm, axes=None, name=None
)

Given a tensor t, and a maximum clip value clip_norm, this operation normalizes t so that its L2-norm is less than or equal to clip_norm, along the dimensions given in axes. Specifically, in the default case where all dimensions are used for calculation, if the L2-norm of t is already less than or equal to clip_norm, then t is not modified. If the L2-norm is greater than clip_norm, then this operation returns a tensor of the same type and shape as t with its values set to:

t * clip_norm / l2norm(t)

In this case, the L2-norm of the output tensor is clip_norm.

As another example, if t is a matrix and axes == [1], then each row of the output will have L2-norm less than or equal to clip_norm. If axes == [0] instead, each column of the output will be clipped.

This operation is typically used to clip gradients before applying them with an optimizer.