Set operations in Numeric

[George Sakkis]

Is there a way to handle numeric (or numarray or numpy) arrays as sets
and compute efficiently their intersection, union, etc. ? I hope there
is a faster way than s = array(set(A) & set(B)). Can this be done with
masked arrays maybe ? I've never used them though and browsing through
the docs didn't make clear if it is possible.

Thanks,
George

[Robert Kern]

Re: Set operations in Numeric

George Sakkis wrote:

Is there a way to handle numeric (or numarray or numpy) arrays as sets
and compute efficiently their intersection, union, etc. ? I hope there
is a faster way than s = array(set(A) & set(B)). Can this be done with
masked arrays maybe ? I've never used them though and browsing through
the docs didn't make clear if it is possible.

You'll probably want to ask such questions on the numpy list:

http://www.scipy.org/Mailing_Lists

Robert Cimrman has implemented a number of set operations based on sorting.

http://svn.scipy.org/svn/scipy/trunk/Lib/sandbox/arraysetops/arraysetops.py

--
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
that is made terrible by our own mad attempt to interpret it as though it had
an underlying truth."
-- Umberto Eco

[George Sakkis]

Re: Set operations in Numeric

Robert Kern wrote:

George Sakkis wrote:

Is there a way to handle numeric (or numarray or numpy) arrays as sets
and compute efficiently their intersection, union, etc. ? I hope there
is a faster way than s = array(set(A) & set(B)). Can this be done with
masked arrays maybe ? I've never used them though and browsing through
the docs didn't make clear if it is possible.

>
You'll probably want to ask such questions on the numpy list:
>

http://www.scipy.org/Mailing_Lists

>
Robert Cimrman has implemented a number of set operations based on sorting.
>
http://svn.scipy.org/svn/scipy/trunk...arraysetops.py

Thank you so much, these fit the bill perfectly !

George