larray.Array.unique

Array.unique(axes=None, sort=False, sep='_') Array[source]

Return unique values (optionally along axes).

Parameters
axesaxis reference (int, str, Axis) or sequence of them, optional

Axis or axes along which to compute unique values. Defaults to None (all axes).

sortbool, optional

Whether to sort unique values. Defaults to False. Sorting is not implemented yet for unique() along multiple axes.

sepstr, optional

Separator when several labels need to be combined. Defaults to ‘_’.

Returns
Array

array with unique values

Examples

>>> arr = Array([[0, 2, 0, 0],
...              [1, 1, 1, 0]], 'a=a0,a1;b=b0..b3')
>>> arr
a\b  b0  b1  b2  b3
 a0   0   2   0   0
 a1   1   1   1   0

By default unique() returns the first occurrence of each unique value in the order it appears:

>>> arr.unique()
a_b  a0_b0  a0_b1  a1_b0
         0      2      1

To sort the unique values, use the sort argument:

>>> arr.unique(sort=True)
a_b  a0_b0  a1_b0  a0_b1
         0      1      2

One can also compute unique sub-arrays (i.e. combination of values) along axes. In our example the a0=0, a1=1 combination appears twice along the ‘b’ axis, so ‘b2’ is not returned:

>>> arr.unique('b')
a\b  b0  b1  b3
 a0   0   2   0
 a1   1   1   0
>>> arr.unique('b', sort=True)
a\b  b3  b0  b1
 a0   0   0   2
 a1   0   1   1