jax.numpy.cumulative_sum

jax.numpy.cumulative_sum(x, /, *, axis=None, dtype=None, include_initial=False)

Cumulative sum along the axis of an array.

JAX implementation of numpy.cumulative_sum().

Parameters:

• x (ArrayLike) – N-dimensional array

• axis (int | None | None) – integer axis along which to accumulate. If x is one-dimensional, this argument is optional and defaults to zero.

• dtype (DTypeLike | None | None) – optional dtype of the output.

• include_initial (bool) – if True, then include the initial value in the cumulative sum. Default is False.

Returns:

An array containing the accumulated values.

Return type:

Array

See also

• jax.numpy.cumsum(): alternative API for cumulative sum.

• jax.numpy.nancumsum(): cumulative sum while ignoring NaN values.

• jax.numpy.add.accumulate(): cumulative sum via the ufunc API.

Examples

>>> x = jnp.array([[1, 2, 3],
...                [4, 5, 6]])
>>> jnp.cumulative_sum(x, axis=1)
Array([[ 1,  3,  6],
       [ 4,  9, 15]], dtype=int32)
>>> jnp.cumulative_sum(x, axis=1, include_initial=True)
Array([[ 0,  1,  3,  6],
       [ 0,  4,  9, 15]], dtype=int32)