CODEWITHSUNDEEP
graphdirected-graph
FriskySaga
FriskySaga

Reputation: 439

In graph theory, what is the vertex that is being pointed to called? What is the vertex that is doing the pointing called?

Suppose we have a directed graph in which vertex A points to vertex B (i.e., A->B). Just to clarify: vertex A has in-degree of 0 and out-degree of 1 while vertex B has in-degree of 1 and out-degree of 0.

Is there a special word to describe vertex A (the vertex that is doing the pointing), and is there also a special word to describe vertex B (the vertex that is being pointed)? Knowing this will help me comment my code cleanly.

Edit: I am not looking for the word that describes a vertex with zero in-degree or zero out-degree. Here is a more refined example: suppose if vertex A points to vertex B which then points to vertex C (i.e., A->B->C). Certainly, vertex B has neither an in-degree of 0 or out-degree of 0. However, in the scope of vertices A and B—meaning if we ignore vertex C—what is vertex A, and what is vertex B? What are the two words that describes vertices A and B's relationship?

Upvotes: 0

Views: 121

Answers (1)

pjs
pjs

Reputation: 19855

You're looking for the terms "head" (the vertex being pointed at) and "tail" (the vertex doing the pointing). See basic terminology on Wikipedia's page about directed graphs.

Upvotes: 2

Related Questions