Skip to content

Add unitedgeweight digraph #886

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

Open
wants to merge 2 commits into
base: main
Choose a base branch
from
+28 −0
Open

Add unitedgeweight digraph #886

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
428c563
Add unitedgeweight digraph
coraaked Dec 1, 2025
7d46ad5
Add 'edge-weighted' output to tests
coraaked Dec 1, 2025
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
1 change: 1 addition & 0 deletions gap/weights.gd
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@ DeclareGlobalFunction("EdgeWeightedDigraph");
DeclareProperty("IsNegativeEdgeWeightedDigraph", IsDigraph and HasEdgeWeights);
DeclareAttribute("EdgeWeightedDigraphTotalWeight",
IsDigraph and HasEdgeWeights);
DeclareAttribute("UnitEdgeWeightedDigraph", IsDigraph);

# 2. Edge Weight Copies
DeclareOperation("EdgeWeightsMutableCopy", [IsDigraph and HasEdgeWeights]);
Expand Down
9 changes: 9 additions & 0 deletions gap/weights.gi
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -79,6 +79,15 @@ InstallMethod(EdgeWeightedDigraphTotalWeight,
[IsDigraph and HasEdgeWeights],
D -> Sum(EdgeWeights(D), Sum));

InstallMethod(UnitEdgeWeightedDigraph,
"for a digraph",
[IsDigraph],
function(D)
local x, unitweights;
unitweights := List(DigraphVertices(D), x -> ListWithIdenticalEntries(OutDegreeOfVertex(D, x), 1));
return(EdgeWeightedDigraph(D, unitweights));
end);

#############################################################################
# 2. Copies of edge weights
#############################################################################
Expand Down
18 changes: 18 additions & 0 deletions tst/testinstall.tst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -541,6 +541,24 @@ gap> AutomorphismGroup(D)
> = Group([(1, 2, 3), (1, 2), (4, 5, 6), (4, 5), (1, 4)(2, 5)(3, 6)]);
true

# UnitEdgeWeightedDigraph
gap> D := UnitEdgeWeightedDigraph(Digraph([[2],[1,3],[1]]));
<immutable edge-weighted digraph with 3 vertices, 4 edges>
gap> EdgeWeights(D);
[ [ 1 ], [ 1, 1 ], [ 1 ] ]
gap> D := UnitEdgeWeightedDigraph(Digraph([[3,4],[1,3,4],[2,4],[1,2,3]]));
<immutable edge-weighted digraph with 4 vertices, 10 edges>
gap> EdgeWeights(D);
[ [ 1, 1 ], [ 1, 1, 1 ], [ 1, 1 ], [ 1, 1, 1 ] ]
gap> D := UnitEdgeWeightedDigraph(EmptyDigraph(4));
<immutable empty edge-weighted digraph with 4 vertices>
gap> EdgeWeights(D);
[ [ ], [ ], [ ], [ ] ]
gap> D := UnitEdgeWeightedDigraph(EdgeWeightedDigraph([[2], []], [[5], []]));
<immutable edge-weighted digraph with 2 vertices, 1 edge>
gap> EdgeWeights(D);
[ [ 1 ], [ ] ]

# SwapDigraphs
gap> C := Digraph(IsMutableDigraph, [[4], [5], [1, 2], [], []]);;
gap> D := Digraph(IsMutableDigraph, [[2, 3, 4], [1, 3, 4, 5], [1, 2], [5], [4]]);;
Expand Down
Loading