# tf.unstack

tf.unstack(
value,
num=None,
axis=0,
name='unstack'
)


Defined in tensorflow/python/ops/array_ops.py.

See the guide: Tensor Transformations > Slicing and Joining

Unpacks the given dimension of a rank-R tensor into rank-(R-1) tensors.

Unpacks num tensors from value by chipping it along the axis dimension. If num is not specified (the default), it is inferred from value's shape. If value.shape[axis] is not known, ValueError is raised.

For example, given a tensor of shape (A, B, C, D);

If axis == 0 then the i'th tensor in output is the slice value[i, :, :, :] and each tensor in output will have shape (B, C, D). (Note that the dimension unpacked along is gone, unlike split).

If axis == 1 then the i'th tensor in output is the slice value[:, i, :, :] and each tensor in output will have shape (A, C, D). Etc.

This is the opposite of stack. The numpy equivalent is

tf.unstack(x, n) = np.unstack(x)


#### Args:

• value: A rank R > 0 Tensor to be unstacked.
• num: An int. The length of the dimension axis. Automatically inferred if None (the default).
• axis: An int. The axis to unstack along. Defaults to the first dimension. Negative values wrap around, so the valid range is [-R, R).
• name: A name for the operation (optional).

#### Returns:

The list of Tensor objects unstacked from value.

#### Raises:

• ValueError: If num is unspecified and cannot be inferred.
• ValueError: If axis is out of the range [-R, R).