Edge weight scale is different between Graph and Preview

Edge weight appears differently in Graph and Preview. In Graph the scale makes different weight appears more different and therefore improve readability. The formula is like this, just scale it between 0.4 - 8

MIN = 0.4
MAX = 8
min = minimum edge weight in the graph
max = maximum edge weight in the graph
w = edge's weight
s = the scale the user can configure

ratio= (MAX - MIN) / (max - min)
weight = ((w - min) * ratio+ MIN) * s;