Function Repository Resource:

EdgeBetweenQ

Quickly test for existence of an edge between two vertices

Contributed by: Michael Sollami

ResourceFunction["EdgeBetweenQ"][g,e]

yields True if e connects two vertices in the graph g and False otherwise.

Details and Options

ResourceFunction["EdgeBetweenQ"] works on both Graph and EdgeTaggedGraph objects.

ResourceFunction["EdgeBetweenQ"] runs in time O(1).

Determine if two vertices are connected by any edge:

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$ResourceFunction["EdgeBetweenQ"][g, 1 \[UndirectedEdge] 2]$

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Note that EdgeQ will give False because it takes edge properties, such as tags, into account:

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$EdgeQ[g, 1 \[UndirectedEdge] 2]$

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EdgeBetweenQ works regardless of edge tag or edge type:

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$g = EdgeTaggedGraph[{1 \[UndirectedEdge] 2, 1 \[DirectedEdge] 2, 2 -> 3}]; EdgeList[g]$

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Check whether an edge is part of a large edge-tagged graph:

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