274
个编辑
更改
→Incidence structures
The incidence matrix of an incidence structure C is a matrix B (or its transpose), where p and q are the number of points and lines respectively, such that if the point p<sub>i</sub> and line L<sub>j</sub> are incident and 0 otherwise. In this case, the incidence matrix is also a biadjacency matrix of the Levi graph of the structure. As there is a hypergraph for every Levi graph, and vice versa, the incidence matrix of an incidence structure describes a hypergraph.
The incidence matrix of an incidence structure C is a matrix B (or its transpose), where p and q are the number of points and lines respectively, such that if the point p<sub>i</sub> and line L<sub>j</sub> are incident and 0 otherwise. In this case, the incidence matrix is also a biadjacency matrix of the Levi graph of the structure. As there is a hypergraph for every Levi graph, and vice versa, the incidence matrix of an incidence structure describes a hypergraph.
关联结构''C''的关联矩阵是一个矩阵''B'' (或其转置) ，其中 p 和 q 分别是点和线的数目，如果点 p<sub>i</sub>和线L<sub>j</sub> 是关联的，就为1，否则为0。在这种情况下，关联矩阵也是'''<font color="#ff8000">Levi图 Levi Graph</font>'''的双邻接矩阵的结构。由于每个 Levi图都有一个超图，反之亦然。关联结构的关联矩阵描述了一个超图。
关联结构 ''C'' 的关联矩阵是一个矩阵''B'' (或其转置) ，其中 ''p'' 和 ''q'' 分别是点和线的数目，如果点 p<sub>i</sub>和线L<sub>j</sub> 是关联的，就为1，否则为0。在这种情况下，关联矩阵也是'''<font color="#ff8000">Levi图 Levi Graph</font>''' 的双邻接矩阵的结构。由于每个Levi图都有一个超图，反之亦然。关联结构的关联矩阵描述了一个超图。
==Finite geometries==
==Finite geometries==