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nonzero#

ivy.nonzero(x, /, *, as_tuple=True, size=None, fill_value=0)[source]#

Return the indices of the array elements which are non-zero.

Note

If x has a complex floating-point data type, non-zero elements are those elements having at least one component (real or imaginary) which is non-zero.

Note

If x has a boolean data type, non-zeroelements are those elements which are equal to True.

Parameters:

  • x (Union[Array, NativeArray]) – input array. Must have a positive rank. If x is zero-dimensional, the function must raise an exception.

  • as_tuple (bool, default: True) – if True, the output is returned as a tuple of indices, one for each dimension of the input, containing the indices of the true elements in that dimension. If False, the coordinates are returned in a (N, ndim) array, where N is the number of true elements. Default = True.

  • size (Optional[int], default: None) – if specified, the function will return an array of shape (size, ndim). If the number of non-zero elements is fewer than size, the remaining elements will be filled with fill_value. Default = None.

  • fill_value (Number, default: 0) – when size is specified and there are fewer than size number of elements, the remaining elements in the output array will be filled with fill_value. Default = 0.

Return type:

Union[Tuple[Array], Array]

Returns:

ret – a tuple of k arrays, one for each dimension of x and each of size n (where n is the total number of non-zero elements), containing the indices of the non-zero elements in that dimension. The indices must be returned in row-major, C-style order. The returned array must have the default array index data type.

This function conforms to the Array API Standard. This docstring is an extension of the docstring in the standard.

Both the description and the type hints above assumes an array input for simplicity, but this function is nestable, and therefore also accepts ivy.Container instances in place of any of the arguments.

Examples

With ivy.Array input:

>>> x = ivy.array([0, 10, 15, 20, -50, 0])
>>> y = ivy.nonzero(x)
>>> print(y)
(ivy.array([1, 2, 3, 4]),)

>>> x = ivy.array([[1, 2], [-1, -2]])
>>> y = ivy.nonzero(x)
>>> print(y)
(ivy.array([0, 0, 1, 1]), ivy.array([0, 1, 0, 1]))

>>> x = ivy.array([[0, 2], [-1, -2]])
>>> y = ivy.nonzero(x, as_tuple=False)
>>> print(y)
ivy.array([[0, 1], [1, 0], [1, 1]])

>>> x = ivy.array([0, 1])
>>> y = ivy.nonzero(x, size=2, fill_value=4)
>>> print(y)
(ivy.array([1, 4]),)

With ivy.NativeArray input:

>>> x = ivy.native_array([[10, 20], [10, 0], [0, 0]])
>>> y = ivy.nonzero(x)
>>> print(y)
(ivy.array([0, 0, 1]), ivy.array([0, 1, 0]))

>>> x = ivy.native_array([[0], [1], [1], [0], [1]])
>>> y = ivy.nonzero(x)
>>> print(y)
(ivy.array([1, 2, 4]), ivy.array([0, 0, 0]))

With ivy.Container input:

>>> x = ivy.Container(a=ivy.array([0,1,2,3,0]), b=ivy.array([1,1, 0,0]))
>>> y = ivy.nonzero(x)
>>> print(y)
[{
    a: ivy.array([1, 2, 3]),
    b: ivy.array([0, 1])
}]

Instance Method Examples

With ivy.Array instance method:

>>> x = ivy.array([0,0,0,1,1,1])
>>> y = x.nonzero()
>>> print(y)
(ivy.array([3, 4, 5]),)

With ivy.Container instance method:

>>> x = ivy.Container(a=ivy.array([1,1,1]), b=ivy.native_array([0]))
>>> y = x.nonzero()
>>> print(y)
[{
    a: ivy.array([0, 1, 2]),
    b: ivy.array([])
}]
Array.nonzero(self, /, *, as_tuple=True, size=None, fill_value=0)[source]#

ivy.Array instance method variant of ivy.nonzero. This method simply wraps the function, and so the docstring for ivy.nonzero also applies to this method with minimal changes.

Parameters:

  • self (Array) – input array. Should have a numeric data type.

  • as_tuple (bool, default: True) – if True, the output is returned as a tuple of indices, one for each dimension of the input, containing the indices of the true elements in that dimension. If False, the coordinates are returned in a (N, ndim) array, where N is the number of true elements. Default = True.

  • size (Optional[int], default: None) – if specified, the function will return an array of shape (size, ndim). If the number of non-zero elements is fewer than size, the remaining elements will be filled with fill_value. Default = None.

  • fill_value (Number, default: 0) – when size is specified and there are fewer than size number of elements, the remaining elements in the output array will be filled with fill_value. Default = 0.

Return type:

Union[Tuple[Array], Array]

Returns:

ret – Array containing the indices of the non-zero values.

Container.nonzero(self, /, *, as_tuple=True, size=None, fill_value=0)[source]#

ivy.Container instance method variant of ivy.nonzero. This method simply wraps the function, and so the docstring for ivy.nonzero also applies to this method with minimal changes.

Parameters:

  • self (Container) – input array or container. Should have a numeric data type.

  • as_tuple (Union[bool, Container], default: True) – if True, the output is returned as a tuple of indices, one for each dimension of the input, containing the indices of the true elements in that dimension. If False, the coordinates are returned in a (N, ndim) array, where N is the number of true elements. Default = True.

  • size (Optional[Union[int, Container]], default: None) – if specified, the function will return an array of shape (size, ndim). If the number of non-zero elements is fewer than size, the remaining elements will be filled with fill_value. Default = None.

  • fill_value (Union[Number, Container], default: 0) – when size is specified and there are fewer than size number of elements, the remaining elements in the output array will be filled with fill_value. Default = 0.

Return type:

Container

Returns:

ret – a container containing the indices of the nonzero values.

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