Hi Rick. Very interesting. I am interested in processing some torsion measurements and assess whether variable 1 versus variable 2 had any changes (over-time). My variables have both positive and negative values in the range (0.20, -0.20). When I test out different bases for logs across these values, I get complex values though. This means that I am losing some portion from my real numbers that I can't get back. Any ideas how to assess statistically changes between variables with this range?