spanning_trees does not enumerate spanning trees with edge labels

[rajat1433]

Currently spanning_trees() method does not enumerate spanning trees with their labels , it makes their labels None. This tickets aims to return the correct labels of the edges.

CC: @dcoudert

Component: graph theory

Keywords: enumeration, spanning_trees

Author: Rajat Mittal

Branch/Commit: 957df83

Reviewer: David Coudert

Issue created by migration from https://trac.sagemath.org/ticket/27557

[rajat1433]

Branch: u/gh-rajat1433/27557_spanning_trees

[sagetrac-git]

Commit: 7d295fa

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

7d295fa

labels include

[rajat1433]

comment:3

I have modified the code to include labels and tested on a few examples.

[dcoudert]

comment:4

You should add parameter labels=False to the method so that user get edge labels only when specifically asked for.

[sagetrac-git]

Changed commit from 7d295fa to 2c9f53c

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

2c9f53c

added labels option

[rajat1433]

comment:6

added labels=False option

[dcoudert]

comment:7

2 remarks:

• the text for the doctest could provide more information like Edges of the spanning trees can be labeled or unlabeled (:trac:27557)::

• when calling _recursive_.., you don't need to write labels=labels.

-            return _recursive_spanning_trees(Graph(self, immutable=False, loops=False), forest, labels=labels)
+            return _recursive_spanning_trees(Graph(self, immutable=False, loops=False), forest, labels)

It would be nice to also get spanning_tree_iterator(). May be for another ticket.

[rajat1433]

comment:8

Yes I have opened another ticket in which spanning_tree_iterator needs to be implemented in increasing order of weights. ticket:27532 Hope that gets implemented soon.

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

957df83

updated

[sagetrac-git]

Changed commit from 2c9f53c to 957df83

[dcoudert]

comment:10

LGTM

[vbraun]

Changed branch from u/gh-rajat1433/27557_spanning_trees to 957df83