Adjacency and Degree

The adjacency and degree functionalities that apply to simple graphs (see Adjacency and Degree) similarly apply to multigraphs.

Contents

Adjacency and Degree Functions for Mul-tigraphs

Degree(u) : GrphVert -> RngIntElt
Given a vertex u of a graph G, return the degree of u, ie the number of edges incident to u.
Alldeg(G, n) : GrphMultUnd, RngIntElt -> { GrphVert }
Given a multigraph G, and a non-negative integer n, return the set of all vertices of G that have degree equal to n.
MaximumDegree(G) : GrphMultUnd -> RngIntElt, GrphVert
Maxdeg(G) : GrphMultUnd -> RngIntElt, GrphVert
The maximum of the degrees of the vertices of the multigraph G. This function returns two values: the maximum degree, and a vertex of G having that degree.
MinimumDegree(G) : GrphMultUnd -> RngIntElt, GrphVert
Mindeg(G) : GrphMultUnd -> RngIntElt, GrphVert
The minimum of the degrees of the vertices of the multigraph G. This function returns two values: the minimum degree, and a vertex of G having that degree.
DegreeSequence(G) : GrphMultUnd -> [ { GrphVert } ]
Given a multigraph G such that the maximum degree of any vertex of G is r, return a sequence D of length r + 1, such that D[i], 1 ≤i ≤r + 1, is the number of vertices in G having degree i - 1.
Neighbours(u) : GrphVert -> { GrphVert }
Neighbors(u) : GrphVert -> { GrphVert }
Given a vertex u of a graph G, return the set of vertices of G that are adjacent to u.
IncidentEdges(u) : GrphVert -> { GrphEdge }
Given a vertex u of a graph G, return the set of all edges incident with the vertex u.

Adjacency and Degree Functions for Multidigraphs

InDegree(u) : GrphVert -> RngIntElt
The number of edges directed into the vertex u belonging to a multidigraph.
OutDegree(u) : GrphVert -> RngIntElt
The number of edges of the form [u, v] where u is a vertex belonging to a multidigraph.
MaximumInDegree(G) : GrphMultDir -> RngIntElt, GrphVert
Maxindeg(G) : GrphMultDir -> RngIntElt, GrphVert
The maximum indegree of the vertices of the multidigraph G. This function returns two values: the maximum indegree, and the first vertex of G having that degree.
MinimumInDegree(G) : GrphMultDir -> RngIntElt, GrphVert
Minindeg(G)) : GrphMultDir -> RngIntElt, GrphVert
The minimum indegree of the vertices of the multidigraph G. This function returns two values: the minimum indegree, and the first vertex of G having that degree.
MaximumOutDegree(G) : GrphMultDir -> RngIntElt, GrphVert
Maxoutdeg(G) : GrphMultDir -> RngIntElt, GrphVert
The maximum outdegree of the vertices of the multidigraph G. This function returns two values: the maximum outdegree, and the first vertex of G having that degree.
MinimumOutDegree(G) : GrphMultDir -> RngIntElt, GrphVert
Minoutdeg(G) : GrphMultDir -> RngIntElt, GrphVert
The minimum outdegree of the vertices of the multidigraph G. This function returns two values: the minimum outdegree, and the first vertex of G having that degree.
Degree(u) : GrphVert -> RngIntElt
Given a vertex u belonging to the multidigraph G, return the total degree of u, i.e. the sum of the in--degree and out--degree for u.
MaximumDegree(G) : GrphMultDir -> RngIntElt, GrphVert
Maxdeg(G) : GrphMultDir -> RngIntElt, GrphVert
The maximum total degree of the vertices of the multidigraph G. This function returns two values: the maximum total degree, and the first vertex of G having that degree.
MinimumDegree(G) : GrphMultDir -> RngIntElt, GrphVert
Mindeg(G) : GrphMultDir -> RngIntElt, GrphVert
The minimum total degree of the vertices of the multidigraph G. This function returns two values: the minimum total degree, and the first vertex of G having that degree.
Alldeg(G, n) : GrphMultDir, RngIntElt -> { GrphVert }
Given a multidigraph G, and a non--negative integer n, return the set of all vertices of G that have total degree equal to n.
DegreeSequence(G) : GrphMultDir -> [ GrphVert ]
Given a multidigraph G such that the maximum degree of any vertex of G is r, return a sequence D of length r + 1, such that D[i], 1 ≤i ≤r + 1, is the number of vertices in G having degree i - 1.
InNeighbours(u) : GrphVert -> { GrphVert }
InNeighbors(u) : GrphVert -> { GrphVert }
Given a vertex u of a multidigraph G, return the set containing all vertices v such that [v, u] is an edge in G, i.e. the initial vertex of all edges that are directed into the vertex u.
OutNeighbours(u) : GrphVert -> { GrphVert }
OutNeighbors(u) : GrphVert -> { GrphVert }
Given a vertex u of the multidigraph G, return the set of vertices v of G such that [u, v] is an edge in G, i.e. the set of vertices v that are terminal vertices of edges directed from u to v.
IncidentEdges(u) : GrphVert -> { GrphEdge }
Given a vertex u of a graph G, return the set of all edges incident with the vertex u, that is, the set of all edges incident into u and incident from u.
V2.28, 13 July 2023