Networks and Matrices Flashcards
nodes or vertices
the points on a network
edge
a line joining to nodes or vertices
faces or regions
edges divide a graph up into seperate faces or regions
loop
an edge that starts and ends at the same vertex or edge
multiple edges
2 or more edges that connect to the same vertices
weighted graph/weighted network
graphs that have amounts or distances or some information on each edge
directed edges or arcs
an edge with significant direction shown with an arrow
directed graph/network or digraph
any graph involving directed edges (or more)
undirected graph/network
any graph with no directed edges
simple graph/network
a graph or network with no loops, multiple edges or direction
open walk
a walk which does not start and end at the same vertex
closed walk
any walk that starts and ends at the same vertex
open path
a walk that has no repeats of edges or vertices and does not start and end at the same vertex
close path or cycle
a walk that has no repeats of edges or vertices and starts and ends at the same vertex
path length
the number of edges a walk, path or cycle uses
trail
a walk with no repeated edges (may have repeated vertices)
connected graph
an undirected graph where every vertex is connected to one another
disconnected or unconnected graph
a graph where a node or vertex is not joined by an edge
complete graphs
simple graphs in which every vertex is connected to every other
bridge
any edge which when removed makes a network become disconnected
planar graph
a graph that can be drawn in the plane. doesn’t need to be connected. main feature is that it can always be drawn so that no two edges cross
subgraph
when the vertices and edges of graph A are also vertices and edges of graph B, A is said to be subgraph of B
Bipartite graph
a graph whose set of vertices can be split into two distinct groups in such a way that each edge of the graph joins a vertex in the first group to vertex in the second group
Eularian graph
a connected graph is eulerian if it has a closed trail that includes every edge once only
eularian trail
a connected graph that travels every edge once and only once, repeated vertices permitted, is a eulerian trail
traversibility
to be able to complete all edges without repeat
semi eulerian
a connected graph that’s an open trail that includes every edge only once is called semi eularian. they have two odd vertices and start and end at different odd vertices
Hamiltonian path
a path in a graph that visits every vertex in a graph only once, with the possible exception of visiting the first vertex again at the end, thus making the path a cycle
Hamiltonian cycle
a Hamiltonian cycle is a closed path that includes each vertex in a graph (except the first) only once
semi hamiltonian
an open path that includes every vertex in a graph once