Encode an adjacency matrix for a directed graph into a symmetric matrix.
Usage
EncodeDirectedGraph(matrix, P)
Arguments
matrix
square matrix
P
permutation vector
Value
The return value is a symmetric matrix representing the encoded input matrix.
Details
This function encodes an adjacency matrix for a directed graph into a symmetric matrix. Currently only binary directed graphs are implemented. The adjacency matrix of a binary directed graph has elements 0, 1. The same graph can be represented by a symmetric adjacency matrix with elements -1, 0, 1, with the sign of the entry indicating the direction of the link. The result is obtained by setting entries (i, j) and (j, i) of the target matrix m' to 1 if entry m[i, j] = 1 and P[i] > P[j] and to -1 if m[i, j] = 1 and P[j] > P[i].