unique_values¶
- unique_values(x: array, /) array ¶
Returns the unique elements of an input array
x
.Data-dependent output shape
The shapes of two of the output arrays for this function depend on the data values in the input array; hence, array libraries which build computation graphs (e.g., JAX, Dask, etc.) may find this function difficult to implement without knowing array values. Accordingly, such libraries may choose to omit this function. See Data-dependent output shapes section for more details.
Note
Uniqueness should be determined based on value equality (see
equal()
). For input arrays having floating-point data types, value-based equality implies the following behavior.As
nan
values compare asFalse
,nan
values should be considered distinct.As complex floating-point values having at least one
nan
component compare asFalse
, complex floating-point values havingnan
components should be considered distinct.As
-0
and+0
compare asTrue
, signed zeros should not be considered distinct, and the corresponding unique element will be implementation-dependent (e.g., an implementation could choose to return-0
if-0
occurs before+0
).
- Parameters:
x (array) – input array. If
x
has more than one dimension, the function must flattenx
and return the unique elements of the flattened array.- Returns:
out (array) – a one-dimensional array containing the set of unique elements in
x
. The returned array must have the same data type asx
.Note
The order of unique elements is not specified and may vary between implementations.
Notes
Changed in version 2022.12: Added complex data type support.
Changed in version 2023.12: Required that the output array must be one-dimensional.