snowkylin/line

second order similarity issue

yfyang86 opened this issue · 2 comments

yfyang86 commented

When we handle the second order similarity, why we need a random switch node strategy (i.e. beginning/ending nodes)?

line/utils.py

Line 41 in 4cdfa7a

if np.random.rand() > 0.5: # important: second-order proximity is for directed edge

In the original paper, it enables developers to utilize the homogenous graph ("an undirected edge can
be considered as two directed edges with opposite directions and equal weights").

snowkylin commented

This only applies when G is an undirected graph (nx.Graph rather than nx.DiGraph). This "switch node strategy" is equal to dividing an undirected edge to two directed edges with opposite directions and equal weights.

bruceli518 commented

I also can't understand this operation, no matter switching the head and tail nodes or not, you only input the edge in one direction. But in the original paper, it said if the graph is undirected, you are supposed to input an edge in two directions.