jax.numpy.nanprod#

jax.numpy.nanprod(a, axis=None, dtype=None, out=None, keepdims=False, initial=None, where=None)[source]#

Return the product of the array elements along a given axis, ignoring NaNs.

JAX implementation of numpy.nanprod().

Parameters:

  • a (ArrayLike) – Input array.

  • axis (Axis) – int or sequence of ints, default=None. Axis along which the product is computed. If None, the product is computed along the flattened array.

  • dtype (DTypeLike | None) – The type of the output array. Default=None.

  • keepdims (bool) – bool, default=False. If True, reduced axes are left in the result with size 1.

  • initial (ArrayLike | None) – int or array, default=None. Initial value for the product.

  • where (ArrayLike | None) – array of boolean dtype, default=None. The elements to be used in the product. Array should be broadcast compatible to the input.

  • out (None) – Unused by JAX.

Returns:

An array containing the product of array elements along the given axis, ignoring NaNs. If all elements along the given axis are NaNs, returns 1.

Return type:

Array

See also

  • jax.numpy.nanmin(): Compute the minimum of array elements along a given axis, ignoring NaNs.

  • jax.numpy.nanmax(): Compute the maximum of array elements along a given axis, ignoring NaNs.

  • jax.numpy.nansum(): Compute the sum of array elements along a given axis, ignoring NaNs.

  • jax.numpy.nanmean(): Compute the mean of array elements along a given axis, ignoring NaNs.

Examples

By default, jnp.nanprod computes the product of elements along the flattened array.

>>> nan = jnp.nan
>>> x = jnp.array([[nan, 3, 4, nan],
...                [5, nan, 1, 3],
...                [2, 1, nan, 1]])
>>> jnp.nanprod(x)
Array(360., dtype=float32)

If axis=1, the product will be computed along axis 1.

>>> jnp.nanprod(x, axis=1)
Array([12., 15.,  2.], dtype=float32)

If keepdims=True, ndim of the output will be same of that of the input.

>>> jnp.nanprod(x, axis=1, keepdims=True)
Array([[12.],
       [15.],
       [ 2.]], dtype=float32)

To include only specific elements in computing the maximum, you can use where.

>>> where=jnp.array([[1, 0, 1, 0],
...                  [0, 0, 1, 1],
...                  [1, 1, 1, 0]], dtype=bool)
>>> jnp.nanprod(x, axis=1, keepdims=True, where=where)
Array([[4.],
       [3.],
       [2.]], dtype=float32)

If where is False at all elements, jnp.nanprod returns 1 along the given axis.

>>> where = jnp.array([[False],
...                    [False],
...                    [False]])
>>> jnp.nanprod(x, axis=0, keepdims=True, where=where)
Array([[1., 1., 1., 1.]], dtype=float32)