250 likes | 795 Views
Vertex Edge Graphs. What is a vertex-edge graph?. A collection of points, some of which are joined by line segments or curves Examples:. Vertex. A point on the graph. Edge . A line segment or curve connecting the vertices of a graph. In the Real-World.
E N D
What is a vertex-edge graph? • A collection of points, some of which are joined by line segments or curves • Examples:
Vertex • A point on the graph.
Edge • A line segment or curve connecting the vertices of a graph.
In the Real-World • Vertices may represent things such as people or places. • Edges may represent connections such as roads or relationships. What are the edges, and what do they represent? What about the vertices?
Complete Graph • A graph in which every vertex is adjacent to every other vertex. • Which of these is complete? A B
Digraph • A directed vertex edge graph
Degree of the Vertex • The number of edges that enter a vertex. What is the degree of vertex A? What is the degree of vertex C? 2 4
Real World Example • The vertex edge graph below represents five people: Bob (B), Dustin (D), Mike (M), Sue (S) and Tammy (T). • An edge connecting two vertices indicates that those two people have a class together.
Who has a class with Mike? Tammy & Sue
Who does not have a class with Bob? Tammy & Mike
Using Matrices to Represent a Vertex-Edge Graph • We can use an adjacency matrix to represent the vertex-edge graph. • Step 1: Create a matrix listing all vertices in the row and column. • Step 2: Fill in the matrix listing the number of relationships between the two points. • If they share an edge, there will be a “1” • If there is no relationship, there will be a “0”
Create a Matrix using the following Vertex-Edge Graph: R S V T U
Drawing a Vertex-Edge Graph • Use the following matrix to create the vertex-edge graph that corresponds.
Drawing a Vertex-Edge Graph • Use the following matrix to create the vertex-edge graph that corresponds.
Extended Relationships • A railway serves four cities: Harrisburg, Baltimore, Philadelphia and Atlantic City. Trains travel between Harrisburg and Baltimore, Harrisburg and Philadelphia, and Philadelphia and Atlantic City. • Draw a vertex edge graph and it’s adjacency matrix to represent this situation.
Railway Continued… • If we take , we can see the relationship that is formed by using 2 trains. • What relationship would give?
Summary3-2-1 • On a separate sheet of paper to turn in, list: • 3 vocabulary words you have learned and their relationship to the vertex-edge graph • 2 reasons to use a vertex-edge graph • 1 real-world example of a vertex-edge graph