Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Fix planarity #696

Merged
merged 14 commits into from
Sep 5, 2024
Merged

Fix planarity #696

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
14 commits
Select commit Hold shift + click to select a range
82f48ab
Planar embed works for non-antisymmetric digraphs
Joseph-Edwards Aug 30, 2024
01103c0
Update tests
Joseph-Edwards Aug 30, 2024
42f6e69
Remove loops
Joseph-Edwards Aug 31, 2024
4bb8a6a
Update doc
Joseph-Edwards Aug 31, 2024
97a9674
Check attributes before making mutable copy
Joseph-Edwards Sep 2, 2024
8929b8d
Add NrAdjacencies
Joseph-Edwards Sep 2, 2024
43cfd86
Update gap/attr.gi
james-d-mitchell Sep 3, 2024
b0357a6
Reduce the amount we copy digraphs
Joseph-Edwards Sep 4, 2024
58f9289
fix spelling
Joseph-Edwards Sep 4, 2024
b9d5dc8
Add mult-digraph check
Joseph-Edwards Sep 4, 2024
32f8e54
Fix edge cases
Joseph-Edwards Sep 4, 2024
73ba5ea
Correct function call in manual example
Joseph-Edwards Sep 4, 2024
497d955
Add forward decl
Joseph-Edwards Sep 4, 2024
de62666
Remove random graph from test
Joseph-Edwards Sep 5, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
42 changes: 42 additions & 0 deletions doc/attr.xml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -138,6 +138,48 @@ gap> DigraphNrEdges(D);
</ManSection>
<#/GAPDoc>

<#GAPDoc Label="DigraphNrAdjacencies">
<ManSection>
<Attr Name="DigraphNrAdjacencies" Arg="digraph" />
<Returns>An integer.</Returns>
<Description> Returns the number of sets <M>\{u, v\}</M> of vertices of the digraph <A>digraph</A>, such that
either <M>(u, v)</M> or <M>(v, u)</M> is an edge. The following equality holds for
any digraph <C>D</C> with no multiple edges: <C>DigraphNrAdjacencies(D) * 2 - DigraphNrLoops(D)
= DigraphNrEdges(DigraphSymmetricClosure(D))</C>.
<Example><![CDATA[
gap> gr := Digraph([
> [1, 3, 4, 5], [1, 2, 3, 5], [2, 4, 5], [2, 4, 5], [1]]);;
gap> DigraphNrAdjacencies(gr);
13
gap> DigraphNrAdjacencies(gr) * 2 - DigraphNrLoops(gr) =
> DigraphNrEdges(DigraphSymmetricClosure(gr));
true
]]></Example>
</Description>
</ManSection>
<#/GAPDoc>

<#GAPDoc Label="DigraphNrAdjacenciesWithoutLoops">
<ManSection>
<Attr Name="DigraphNrAdjacenciesWithoutLoops" Arg="digraph" />
<Returns>An integer.</Returns>
<Description> Returns the number of sets <M>\{u, v\}</M> of vertices of the digraph <A>digraph</A>, such that
<M>u \neq v</M> and either <M>(u, v)</M> or <M>(v, u)</M> is an edge. The following equality holds for
any digraph <C>D</C> with no multiple edges: <C>DigraphNrAdjacenciesWithoutLoops(D) * 2 + DigraphNrLoops(D)
= DigraphNrEdges(DigraphSymmetricClosure(D))</C>.
<Example><![CDATA[
gap> gr := Digraph([
> [1, 3, 4, 5], [1, 2, 3, 5], [2, 4, 5], [2, 4, 5], [1]]);;
gap> DigraphNrAdjacenciesWithoutLoops(gr);
10
gap> DigraphNrAdjacenciesWithoutLoops(gr) * 2 + DigraphNrLoops(gr) =
> DigraphNrEdges(DigraphSymmetricClosure(gr));
true
]]></Example>
</Description>
</ManSection>
<#/GAPDoc>

<#GAPDoc Label="DigraphNrLoops">
<ManSection>
<Attr Name="DigraphNrLoops" Arg="digraph"/>
Expand Down
124 changes: 64 additions & 60 deletions doc/planar.xml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -112,14 +112,15 @@ true
<Attr Name="KuratowskiPlanarSubdigraph" Arg="digraph"/>
<Returns>A list or <K>fail</K>.</Returns>
<Description>
<C>KuratowskiPlanarSubdigraph</C> returns the immutable list of
lists of out-neighbours of a (not necessarily induced) subdigraph of the
digraph <A>digraph</A> that witnesses the fact that <A>digraph</A> is not
planar, or <K>fail</K> if <A>digraph</A> is planar. In other words,
<C>KuratowskiPlanarSubdigraph</C> returns the out-neighbours of a
subdigraph of <A>digraph</A> that is homeomorphic to the complete graph
with <C>5</C> vertices, or to the complete bipartite graph with vertex sets
of sizes <C>3</C> and <C>3</C>. <P/>
<C>KuratowskiPlanarSubdigraph</C> returns the immutable list of lists of
out-neighbours of an induced subdigraph (excluding multiple edges and loops)
of the digraph <A>digraph</A> that witnesses the fact that <A>digraph</A> is
not planar, or <K>fail</K> if <A>digraph</A> is planar. In other words,
<C>KuratowskiPlanarSubdigraph</C> returns the out-neighbours of a subdigraph
of <A>digraph</A> that is homeomorphic to the complete graph with <C>5</C>
vertices, or to the complete bipartite graph with vertex sets of sizes
<C>3</C> and <C>3</C>.
<P/>

The directions and multiplicities of any edges in <A>digraph</A> are
ignored when considering whether or not <A>digraph</A> is planar. <P/>
Expand All @@ -145,8 +146,8 @@ gap> D := Digraph([[2, 4, 7, 9, 10], [1, 3, 4, 6, 9, 10], [6, 10],
gap> IsPlanarDigraph(D);
false
gap> KuratowskiPlanarSubdigraph(D);
[ [ 2, 9, 7 ], [ 3 ], [ 6 ], [ 5, 9 ], [ 6 ], [ ], [ 4 ],
[ 7, 9, 3 ], [ ], [ ] ]
[ [ 2, 9, 7 ], [ 1, 3 ], [ 6 ], [ 5, 9 ], [ 6, 4 ], [ 3, 5 ], [ 4 ],
[ 7, 9, 3 ], [ 8 ], [ ] ]
gap> D := Digraph(IsMutableDigraph, [[3, 5, 10], [8, 9, 10], [1, 4],
> [3, 6], [1, 7, 11], [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<mutable digraph with 11 vertices, 25 edges>
Expand All @@ -160,8 +161,8 @@ gap> D := Digraph(IsMutableDigraph, [[2, 4, 7, 9, 10],
gap> IsPlanarDigraph(D);
false
gap> KuratowskiPlanarSubdigraph(D);
[ [ 2, 9, 7 ], [ 3 ], [ 6 ], [ 5, 9 ], [ 6 ], [ ], [ 4 ],
[ 7, 9, 3 ], [ ], [ ] ]
[ [ 2, 9, 7 ], [ 1, 3 ], [ 6 ], [ 5, 9 ], [ 6, 4 ], [ 3, 5 ], [ 4 ],
[ 7, 9, 3 ], [ 8 ], [ ] ]
]]></Example>
</Description>
</ManSection>
Expand All @@ -173,17 +174,18 @@ gap> KuratowskiPlanarSubdigraph(D);
<Returns>A list or <K>fail</K>.</Returns>
<Description>
<C>KuratowskiOuterPlanarSubdigraph</C> returns the immutable list of
immutable lists of out-neighbours of a (not necessarily induced)
subdigraph of the digraph <A>digraph</A> that witnesses the fact
that <A>digraph</A> is not outer planar, or <K>fail</K> if
<A>digraph</A> is outer planar. In other words,
immutable lists of out-neighbours of an induced subdigraph (excluding
multiple edges and loops) of the digraph <A>digraph</A> that witnesses the
fact that <A>digraph</A> is not outer planar, or <K>fail</K> if
<A>digraph</A> is outer planar. In other words,
<C>KuratowskiOuterPlanarSubdigraph</C> returns the out-neighbours of a
subdigraph of <A>digraph</A> that is homeomorphic to the complete graph
with <C>4</C> vertices, or to the complete bipartite graph with vertex sets
of sizes <C>2</C> and <C>3</C>. <P/>
subdigraph of <A>digraph</A> that is homeomorphic to the complete graph with
<C>4</C> vertices, or to the complete bipartite graph with vertex sets of
sizes <C>2</C> and <C>3</C>.
<P/>

The directions and multiplicities of any edges in <A>digraph</A> are
ignored when considering whether or not <A>digraph</A> is outer planar.
The directions and multiplicities of any edges in <A>digraph</A> are ignored
when considering whether or not <A>digraph</A> is outer planar.
<P/>

See also
Expand All @@ -201,23 +203,23 @@ gap> D := Digraph([[3, 5, 10], [8, 9, 10], [1, 4], [3, 6],
> [1, 7, 11], [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<immutable digraph with 11 vertices, 25 edges>
gap> KuratowskiOuterPlanarSubdigraph(D);
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4 ], [ 6 ], [ 11 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4, 1 ], [ 6, 3 ], [ 1, 11 ],
[ 7, 4 ], [ 8, 6 ], [ 2, 7 ], [ 11, 2 ], [ 2, 1 ], [ 5, 9 ] ]
gap> D := Digraph([[2, 4, 7, 9, 10], [1, 3, 4, 6, 9, 10], [6, 10],
> [2, 5, 8, 9], [1, 2, 3, 4, 6, 7, 9, 10], [3, 4, 5, 7, 9, 10],
> [3, 4, 5, 6, 9, 10], [3, 4, 5, 7, 9], [2, 3, 5, 6, 7, 8], [3, 5]]);
<immutable digraph with 10 vertices, 50 edges>
gap> IsOuterPlanarDigraph(D);
false
gap> KuratowskiOuterPlanarSubdigraph(D);
[ [ ], [ ], [ ], [ 8, 9 ], [ ], [ ], [ 9, 4 ], [ 7, 9 ], [ ],
[ ] ]
[ [ ], [ ], [ ], [ 8, 9 ], [ ], [ ], [ 9, 4 ], [ 7, 9, 4 ],
[ 8, 7 ], [ ] ]
gap> D := Digraph(IsMutableDigraph, [[3, 5, 10], [8, 9, 10], [1, 4],
> [3, 6], [1, 7, 11], [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<mutable digraph with 11 vertices, 25 edges>
gap> KuratowskiOuterPlanarSubdigraph(D);
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4 ], [ 6 ], [ 11 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4, 1 ], [ 6, 3 ], [ 1, 11 ],
[ 7, 4 ], [ 8, 6 ], [ 2, 7 ], [ 11, 2 ], [ 2, 1 ], [ 5, 9 ] ]
gap> D := Digraph(IsMutableDigraph, [[2, 4, 7, 9, 10],
> [1, 3, 4, 6, 9, 10], [6, 10], [2, 5, 8, 9],
> [1, 2, 3, 4, 6, 7, 9, 10], [3, 4, 5, 7, 9, 10],
Expand All @@ -226,8 +228,8 @@ gap> D := Digraph(IsMutableDigraph, [[2, 4, 7, 9, 10],
gap> IsOuterPlanarDigraph(D);
false
gap> KuratowskiOuterPlanarSubdigraph(D);
[ [ ], [ ], [ ], [ 8, 9 ], [ ], [ ], [ 9, 4 ], [ 7, 9 ], [ ],
[ ] ]]]></Example>
[ [ ], [ ], [ ], [ 8, 9 ], [ ], [ ], [ 9, 4 ], [ 7, 9, 4 ],
[ 8, 7 ], [ ] ]]]></Example>
</Description>
</ManSection>
<#/GAPDoc>
Expand All @@ -237,14 +239,14 @@ gap> KuratowskiOuterPlanarSubdigraph(D);
<Attr Name="PlanarEmbedding" Arg="digraph"/>
<Returns>A list or <K>fail</K>.</Returns>
<Description>
If <A>digraph</A> is a planar digraph, then
<C>PlanarEmbedding</C> returns the immutable list of lists of
out-neighbours of a subdigraph of <A>digraph</A> such that each vertex's
neighbours are given in clockwise order. If <A>digraph</A> is not planar,
then <K>fail</K> is returned. <P/>
If <A>digraph</A> is a planar digraph, then <C>PlanarEmbedding</C> returns
the immutable list of lists of out-neighbours of <A>digraph</A> (excluding
multiple edges and loops) such that each vertex's neighbours are given in
clockwise order. If <A>digraph</A> is not planar, then <K>fail</K> is
returned. <P/>

The directions and multiplicities of any edges in <A>digraph</A> are
ignored by <C>PlanarEmbedding</C>.
The directions and multiplicities of any edges in <A>digraph</A> are ignored
by <C>PlanarEmbedding</C>.
<P/>

See also
Expand All @@ -260,8 +262,8 @@ gap> D := Digraph([[3, 5, 10], [8, 9, 10], [1, 4], [3, 6],
> [1, 7, 11], [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<immutable digraph with 11 vertices, 25 edges>
gap> PlanarEmbedding(D);
[ [ 3, 10, 5 ], [ 10, 8, 9 ], [ 4 ], [ 6 ], [ 11, 7 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 10, 5 ], [ 10, 8, 9 ], [ 4, 1 ], [ 6, 3 ], [ 1, 11, 7 ],
[ 7, 4 ], [ 8, 6 ], [ 7, 2 ], [ 2, 11 ], [ 1, 2 ], [ 9, 5 ] ]
gap> D := Digraph([[2, 4, 7, 9, 10], [1, 3, 4, 6, 9, 10], [6, 10],
> [2, 5, 8, 9], [1, 2, 3, 4, 6, 7, 9, 10], [3, 4, 5, 7, 9, 10],
> [3, 4, 5, 6, 9, 10], [3, 4, 5, 7, 9], [2, 3, 5, 6, 7, 8], [3, 5]]);
Expand All @@ -272,8 +274,8 @@ gap> D := Digraph(IsMutableDigraph, [[3, 5, 10], [8, 9, 10], [1, 4],
> [3, 6], [1, 7, 11], [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<mutable digraph with 11 vertices, 25 edges>
gap> PlanarEmbedding(D);
[ [ 3, 10, 5 ], [ 10, 8, 9 ], [ 4 ], [ 6 ], [ 11, 7 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 10, 5 ], [ 10, 8, 9 ], [ 4, 1 ], [ 6, 3 ], [ 1, 11, 7 ],
[ 7, 4 ], [ 8, 6 ], [ 7, 2 ], [ 2, 11 ], [ 1, 2 ], [ 9, 5 ] ]
gap> D := Digraph(IsMutableDigraph, [[2, 4, 7, 9, 10],
> [1, 3, 4, 6, 9, 10], [6, 10], [2, 5, 8, 9],
> [1, 2, 3, 4, 6, 7, 9, 10], [3, 4, 5, 7, 9, 10],
Expand All @@ -292,10 +294,10 @@ fail
<Returns>A list or <K>fail</K>.</Returns>
<Description>
If <A>digraph</A> is an outer planar digraph, then
<C>OuterPlanarEmbedding</C> returns the immutable list of lists
of out-neighbours of a subdigraph of <A>digraph</A> such that each
vertex's neighbours are given in clockwise order. If <A>digraph</A> is not
outer planar, then <K>fail</K> is returned. <P/>
<C>OuterPlanarEmbedding</C> returns the immutable list of lists of
out-neighbours of <A>digraph</A> (excluding multiple edges and loops) such
that each vertex's neighbours are given in clockwise order. If
<A>digraph</A> is not outer planar, then <K>fail</K> is returned. <P/>

The directions and multiplicities of any edges in <A>digraph</A> are
ignored by <C>OuterPlanarEmbedding</C>.
Expand All @@ -321,7 +323,7 @@ gap> D := Digraph([[2, 4, 7, 9, 10], [1, 3, 4, 6, 9, 10], [6, 10],
gap> OuterPlanarEmbedding(D);
fail
gap> OuterPlanarEmbedding(CompleteBipartiteDigraph(2, 2));
[ [ 3, 4 ], [ 4, 3 ], [ ], [ ] ]
[ [ 3, 4 ], [ 4, 3 ], [ 2, 1 ], [ 1, 2 ] ]
gap> D := Digraph(IsMutableDigraph, [[3, 5, 10], [8, 9, 10], [1, 4],
> [3, 6], [1, 7, 11], [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<mutable digraph with 11 vertices, 25 edges>
Expand All @@ -335,7 +337,7 @@ gap> D := Digraph(IsMutableDigraph, [[2, 4, 7, 9, 10],
gap> OuterPlanarEmbedding(D);
fail
gap> OuterPlanarEmbedding(CompleteBipartiteDigraph(2, 2));
[ [ 3, 4 ], [ 4, 3 ], [ ], [ ] ]
[ [ 3, 4 ], [ 4, 3 ], [ 2, 1 ], [ 1, 2 ] ]
]]></Example>
</Description>
</ManSection>
Expand Down Expand Up @@ -369,54 +371,56 @@ gap> D := Digraph([[3, 5, 10], [8, 9, 10], [1, 4], [3, 6], [1, 7, 11],
> [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<immutable digraph with 11 vertices, 25 edges>
gap> SubdigraphHomeomorphicToK4(D);
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4 ], [ 6 ], [ 7, 11 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4, 1 ], [ 6, 3 ], [ 1, 7, 11 ],
[ 7, 4 ], [ 8, 6 ], [ 2, 7 ], [ 11, 2 ], [ 2, 1 ], [ 5, 9 ] ]
gap> SubdigraphHomeomorphicToK23(D);
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4 ], [ 6 ], [ 11 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4, 1 ], [ 6, 3 ], [ 1, 11 ],
[ 7, 4 ], [ 8, 6 ], [ 2, 7 ], [ 11, 2 ], [ 2, 1 ], [ 5, 9 ] ]
gap> D := Digraph([[3, 5, 10], [8, 9, 10], [1, 4], [3, 6], [1, 11],
> [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<immutable digraph with 11 vertices, 24 edges>
gap> SubdigraphHomeomorphicToK4(D);
fail
gap> SubdigraphHomeomorphicToK23(D);
[ [ 3, 10, 5 ], [ 10, 8, 9 ], [ 4 ], [ 6 ], [ 11 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 10, 5 ], [ 10, 8, 9 ], [ 4, 1 ], [ 6, 3 ], [ 11, 1 ],
[ 7, 4 ], [ 8, 6 ], [ 2, 7 ], [ 2, 11 ], [ 1, 2 ], [ 9, 5 ] ]
gap> SubdigraphHomeomorphicToK33(D);
fail
gap> SubdigraphHomeomorphicToK23(NullDigraph(0));
fail
gap> SubdigraphHomeomorphicToK33(CompleteDigraph(5));
fail
gap> SubdigraphHomeomorphicToK33(CompleteBipartiteDigraph(3, 3));
[ [ 4, 6, 5 ], [ 4, 5, 6 ], [ 6, 5, 4 ], [ ], [ ], [ ] ]
[ [ 4, 6, 5 ], [ 4, 5, 6 ], [ 6, 5, 4 ], [ 1, 2, 3 ], [ 3, 2, 1 ],
[ 2, 3, 1 ] ]
gap> SubdigraphHomeomorphicToK4(CompleteDigraph(3));
fail
gap> D := Digraph(IsMutableDigraph, [[3, 5, 10], [8, 9, 10], [1, 4],
> [3, 6], [1, 7, 11], [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<mutable digraph with 11 vertices, 25 edges>
gap> SubdigraphHomeomorphicToK4(D);
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4 ], [ 6 ], [ 7, 11 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4, 1 ], [ 6, 3 ], [ 1, 7, 11 ],
[ 7, 4 ], [ 8, 6 ], [ 2, 7 ], [ 11, 2 ], [ 2, 1 ], [ 5, 9 ] ]
gap> SubdigraphHomeomorphicToK23(D);
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4 ], [ 6 ], [ 11 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 5, 10 ], [ 9, 8, 10 ], [ 4, 1 ], [ 6, 3 ], [ 1, 11 ],
[ 7, 4 ], [ 8, 6 ], [ 2, 7 ], [ 11, 2 ], [ 2, 1 ], [ 5, 9 ] ]
gap> D := Digraph(IsMutableDigraph, [[3, 5, 10], [8, 9, 10], [1, 4],
> [3, 6], [1, 11], [4, 7], [6, 8], [2, 7], [2, 11], [1, 2], [5, 9]]);
<mutable digraph with 11 vertices, 24 edges>
gap> SubdigraphHomeomorphicToK4(D);
fail
gap> SubdigraphHomeomorphicToK23(D);
[ [ 3, 10, 5 ], [ 10, 8, 9 ], [ 4 ], [ 6 ], [ 11 ], [ 7 ], [ 8 ],
[ ], [ 11 ], [ ], [ ] ]
[ [ 3, 10, 5 ], [ 10, 8, 9 ], [ 4, 1 ], [ 6, 3 ], [ 11, 1 ],
[ 7, 4 ], [ 8, 6 ], [ 2, 7 ], [ 2, 11 ], [ 1, 2 ], [ 9, 5 ] ]
gap> SubdigraphHomeomorphicToK33(D);
fail
gap> SubdigraphHomeomorphicToK23(NullDigraph(0));
fail
gap> SubdigraphHomeomorphicToK33(CompleteDigraph(5));
fail
gap> SubdigraphHomeomorphicToK33(CompleteBipartiteDigraph(3, 3));
[ [ 4, 6, 5 ], [ 4, 5, 6 ], [ 6, 5, 4 ], [ ], [ ], [ ] ]
[ [ 4, 6, 5 ], [ 4, 5, 6 ], [ 6, 5, 4 ], [ 1, 2, 3 ], [ 3, 2, 1 ],
[ 2, 3, 1 ] ]
gap> SubdigraphHomeomorphicToK4(CompleteDigraph(3));
fail
]]></Example>
Expand Down
2 changes: 2 additions & 0 deletions doc/z-chap4.xml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,8 @@
<#Include Label="DigraphNrVertices">
<#Include Label="DigraphEdges">
<#Include Label="DigraphNrEdges">
<#Include Label="DigraphNrAdjacencies">
<#Include Label="DigraphNrAdjacenciesWithoutLoops">
<#Include Label="DigraphNrLoops">
<#Include Label="DigraphSinks">
<#Include Label="DigraphSources">
Expand Down
2 changes: 2 additions & 0 deletions gap/attr.gd
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,8 @@ DeclareAttribute("DigraphVertices", IsDigraph);
DeclareAttribute("DigraphNrVertices", IsDigraph);
DeclareAttribute("DigraphEdges", IsDigraph);
DeclareAttribute("DigraphNrEdges", IsDigraph);
DeclareAttribute("DigraphNrAdjacencies", IsDigraph);
DeclareAttribute("DigraphNrAdjacenciesWithoutLoops", IsDigraph);
DeclareAttribute("DigraphNrLoops", IsDigraph);
DeclareAttribute("DigraphHash", IsDigraph);

Expand Down
6 changes: 6 additions & 0 deletions gap/attr.gi
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -701,6 +701,12 @@ function(D)
return m;
end);

InstallMethod(DigraphNrAdjacencies, "for a digraph",
[IsDigraphByOutNeighboursRep], DIGRAPH_NRADJACENCIES);

InstallMethod(DigraphNrAdjacenciesWithoutLoops, "for a digraph",
[IsDigraphByOutNeighboursRep], DIGRAPH_NRADJACENCIESWITHOUTLOOPS);

InstallMethod(DigraphNrLoops,
"for a digraph by out-neighbours",
[IsDigraphByOutNeighboursRep],
Expand Down
Loading
Loading