cupy.unique¶

cupy.unique(ar, return_index=False, return_inverse=False, return_counts=False, axis=None)[source]¶

Find the unique elements of an array.

Returns the sorted unique elements of an array. There are three optional outputs in addition to the unique elements:

the indices of the input array that give the unique values
the indices of the unique array that reconstruct the input array
the number of times each unique value comes up in the input array

Parameters:

ar (array_like) – Input array. This will be flattened if it is not already 1-D.
return_index (bool, optional) – If True, also return the indices of ar (along the specified axis, if provided, or in the flattened array) that result in the unique array.
return_inverse (bool, optional) – If True, also return the indices of the unique array (for the specified axis, if provided) that can be used to reconstruct ar.
return_counts (bool, optional) – If True, also return the number of times each unique item appears in ar.
axis (int or None, optional) – Not supported yet.

Returns:

If there are no optional outputs, it returns the cupy.ndarray of the sorted unique values. Otherwise, it returns the tuple which contains the sorted unique values and followings.

The indices of the first occurrences of the unique values in the original array. Only provided if return_index is True.
The indices to reconstruct the original array from the unique array. Only provided if return_inverse is True.
The number of times each of the unique values comes up in the original array. Only provided if return_counts is True.

Return type:

cupy.ndarray or tuple

Warning

This function may synchronize the device.