jax.lax.dynamic_update_slice#

jax.lax.dynamic_update_slice(operand, update, start_indices)[source]#

Wraps XLA’s DynamicUpdateSlice operator.

Parameters

operand (Array) – an array to slice.
update (Union[Array, ndarray, bool_, number, bool, int, float, complex]) – an array containing the new values to write onto operand.
start_indices (Union[Array, Sequence[Union[Array, ndarray, bool_, number, bool, int, float, complex]]]) – a list of scalar indices, one per dimension.

Return type

Array

Returns

An array containing the slice.

Examples

Here is an example of updating a one-dimensional slice update:

>>> x = jnp.zeros(6)
>>> y = jnp.ones(3)
>>> dynamic_update_slice(x, y, (2,))
Array([0., 0., 1., 1., 1., 0.], dtype=float32)

If the update slice is too large to fit in the array, the start index will be adjusted to make it fit

>>> dynamic_update_slice(x, y, (3,))
Array([0., 0., 0., 1., 1., 1.], dtype=float32)
>>> dynamic_update_slice(x, y, (5,))
Array([0., 0., 0., 1., 1., 1.], dtype=float32)

Here is an example of a two-dimensional slice update:

>>> x = jnp.zeros((4, 4))
>>> y = jnp.ones((2, 2))
>>> dynamic_update_slice(x, y, (1, 2))
Array([[0., 0., 0., 0.],
       [0., 0., 1., 1.],
       [0., 0., 1., 1.],
       [0., 0., 0., 0.]], dtype=float32)