#12571: Implementation of shifted shuffle of permutations
-----------------------------+----------------------------------------------
Reporter: giraudo | Owner: sage-combinat
Type: enhancement | Status: new
Priority: major | Milestone: sage-5.0
Component: combinatorics | Keywords: Permutations; Shuffle
Work_issues: | Upstream: N/A
Reviewer: | Author: Samuele Giraudo
Merged: | Dependencies:
-----------------------------+----------------------------------------------
The shifted shuffle of two permutations can be expressed as a right
permutohedron interval. We implements a method that computes in this way
the shifted shuffle of two permutations.
Note that this improve the efficiency of the former way to compute shifted
shuffle of permutations:
{{{
sage: p1 = Permutations(10).random_element()
sage: p2 = Permutations(7).random_element()
}}}
{{{
sage: _ = [Permutation(p) for p in Word(p1).shifted_shuffle(Word(p2))]
}}}
takes about 19.95 s CPU time on my computer, but
{{{
sage: _ = p1.shifted_shuffle(p2)
}}}
takes about 3.94 s CPU time.
We also implements Loday-Ronco's over and under operations on
permutations.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/12571>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
