expand_dims¶

dragon.expand_dims(
  inputs,
  axis,
  copy=True,
  **kwargs
)[source]¶

Expand the dimensions of input with size 1.

axis could be negative or None:

x = dragon.ones((2, 3, 4, 5))

# axis is the size-1 position in output
print(dragon.expand_dims(x, axis=0).shape)  # (2, 3, 4, 5) -> (1, 2, 3, 4, 5)
print(dragon.expand_dims(x, axis=1).shape)  # (2, 3, 4, 5) -> (2, 1, 3, 4, 5)

# A negative axis is the last-k axis
print(dragon.expand_dims(x, axis=4).shape)   # (2, 3, 4, 5) -> (2, 3, 4, 5, 1)
print(dragon.expand_dims(x, axis=-1).shape)  # Equivalent

# Also, axis could be a sequence of integers
print(dragon.expand_dims(x, axis=[-1, -3]).shape)  # (2, 3, 4, 5) -> (2, 3, 4, 1, 5, 1)

Parameters:

• inputs (dragon.Tensor) – The input tensor.
• axis (Union[int, Sequence[int]]) – The axis to insert the new dimension.
• copy (bool, optional, default=True) – Return a new tensor or call in-place.

Returns:

dragon.Tensor – The output tensor.