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删除2字节 、 2020年8月26日 (三) 10:49
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图的'''<font color="#ff8000">圈空间 Cycle Space</font>'''等j价于其有向关联矩阵的零空间,可以看作是整数或实数或复数上的矩阵。二元循环空间是有向或无向关联矩阵的零空间,也可以看作是二元场上的矩阵。
 
图的'''<font color="#ff8000">圈空间 Cycle Space</font>'''等j价于其有向关联矩阵的零空间,可以看作是整数或实数或复数上的矩阵。二元循环空间是有向或无向关联矩阵的零空间,也可以看作是二元场上的矩阵。
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===Signed and bidirected graphs===
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==Signed and bidirected graphs==
    
The incidence matrix of a [[signed graph]] is a generalization of the oriented incidence matrix. It is the incidence matrix of any [[bidirected graph]] that orients the given signed graph. The column of a positive edge has a 1 in the row corresponding to one endpoint and a −1 in the row corresponding to the other endpoint, just like an edge in an ordinary (unsigned) graph. The column of a negative edge has either a 1 or a −1 in both rows. The line graph and Kirchhoff matrix properties generalize to signed graphs.
 
The incidence matrix of a [[signed graph]] is a generalization of the oriented incidence matrix. It is the incidence matrix of any [[bidirected graph]] that orients the given signed graph. The column of a positive edge has a 1 in the row corresponding to one endpoint and a −1 in the row corresponding to the other endpoint, just like an edge in an ordinary (unsigned) graph. The column of a negative edge has either a 1 or a −1 in both rows. The line graph and Kirchhoff matrix properties generalize to signed graphs.
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