[Geotools-devel] Quantile classification oddities

[Andrea A. <aa...@op...>]

Hi,
I'm having some troubles using the quantile classification algorithm.
As you may know, quantile figures out how to classify a range of numbers
in a way that each class has the same number of features in it.

Consider a case when an attribute has the following values (in different 
features): {0 0 0 0 3 5 7 9}. Then ask the quantile classifier to create 
a 4 intervals classification, and you'll get:
{0 0}
{0 0}
{3 5}
{7 9}
This does not look very nice... I'm wondering if the quantile algorithm 
should consider this and avoid breaking the classes when the the same 
value will keep on appearing on the next class. For most users the 
following classification:
att < 3
3 < att <= 5
5 < att
or put another way:
{0 0 0 0}
{3 5}
{7 9}
thought not made of 3 intervals, would make much more sense.
What I'm wondering is, can we have a quantile function that returns
eventually less intervals but that does not builds odd classes like
the current one?

Cheers
Andrea