Derangements

[sagetrac-amca01]

The current implementation in Sage for derangements is a wrapper for the GAP "derangements" and "number_of_derangements" which is very restrictive. For example, it doesn't allow derangements of arbitrary lists or strings. The documentation observes

"Warning - Wraps GAP - hence mset must be a list of objects that have string representations that can be interpreted by the GAP interpreter. If mset consists of at all complicated Sage objects, this function does not do what you expect. A proper function should be written! (TODO!)"

This file is an attempt to provide that.

CC: @nathanncohen @ppurka

Component: combinatorics

Keywords: derangements

Author: Alasdair McAndrew, Travis Scrimshaw

Reviewer: Ben Salisbury

Merged: sage-5.10.beta1

Issue created by migration from https://trac.sagemath.org/ticket/9005

[sagetrac-amca01]

Work Issues: It does not yet pass all doctests

[sagetrac-amca01]

Attachment: derangements.sage.gz

[tscrim]

Changed work issues from It does not yet pass all doctests to none

[tscrim]

Changed author from Alasdair McAndrew to Alasdair McAndrew, Travis Scrimshaw

[tscrim]

Changed upstream from Not yet reported upstream; Will do shortly. to none

[tscrim]

comment:4

Converted the sage file into a patch and brought it up to our current standards. Ready for review.

[bsalisbury1]

Reviewer: Ben Salisbury

[jdemeyer]

comment:6

The patch is not a proper patch file, patches should be generated using hg export tip.

[tscrim]

comment:7

Attachment: trac_9005-derangements-ts.patch.gz

Sorry about that. Fixed.

[jdemeyer]

Merged: sage-5.10.beta1