uniq

pydl.uniq(x, index=None)[source]

Replicates the IDL UNIQ() function.

Returns the subscripts of the unique elements of an array. The elements must actually be sorted before being passed to this function. This can be done by sorting x explicitly or by passing the array subscripts that sort x as a second parameter.

Parameters
xarray-like

Search this array for unique items.

indexarray-like, optional

This array provides the array subscripts that sort x.

Returns
array-like

The subscripts of x that are the unique elements of x.

Notes

Given a sorted array, and assuming that there is a set of adjacent identical items, uniq() will return the subscript of the last unique item. This charming feature is retained for reproducibility.

References

http://www.harrisgeospatial.com/docs/uniq.html

Examples

>>> import numpy as np
>>> from pydl import uniq
>>> data = np.array([ 1, 2, 3, 1, 5, 6, 1, 7, 3, 2, 5, 9, 11, 1 ])
>>> print(uniq(np.sort(data)))
[ 3  5  7  9 10 11 12 13]