526
个编辑
更改
无编辑摘要
[[Image:Labeled undirected graph.svg|thumb|250px|An undirected graph.]]
[[Image:Labeled undirected graph.svg|thumb|250px|An undirected graph.]]
图：An undirected graph.
图：An undirected graph. 一个无向图。
一个无向图。
In graph theory an [[undirected graph]] has two kinds of incidence matrices: unoriented and oriented.
In graph theory an [[undirected graph]] has two kinds of incidence matrices: unoriented and oriented.
The unoriented incidence matrix (or simply incidence matrix) of an undirected graph is a matrix B, where n and m are the numbers of vertices and edges respectively, such that if the vertex v<sub>i</sub> and edge e<sub>j</sub> are incident and 0 otherwise.
The unoriented incidence matrix (or simply incidence matrix) of an undirected graph is a matrix B, where n and m are the numbers of vertices and edges respectively, such that if the vertex v<sub>i</sub> and edge e<sub>j</sub> are incident and 0 otherwise.
无向图的无向关联矩阵（也称为简单的关联矩阵）''B''，其中 ''n'' 和 ''m'' 分别是顶点和边的数目，如果顶点 v<sub>i</sub> 和边 e<sub>j</sub>是关联的，则结果为1，否则为0。