Specify extreme values of range beyond what's in data?

[mars0i]

I want to set a specific maximum and minimum for a range that I'm using for ranking. Gephi chooses the extreme values from my data, but I want to set the maximum and minimum to 1 and -1 respectively, even when those are not the max and min values in the data. Is there a way to do this?

A workaround is for me to include nodes in the graph that have the extreme values that I want, but that's not a desirable solution since it introduces nodes and edges that don't belong in the graph. I could make them transparent, I would imagine, but they will still affect layouts.