Hi all, in several vehicles, I measured the engine torque and speed and the engaged gear while it was driven for around 100km/h. I computed the average engine speed and torque of all the times the vehicle was run with each gear and also I computed the relative frequency of the gear used. So for each vehicle, I have the following plots: https://s29.postimg.org/tnyfcdron/untitled.jpg I have around 300 repetitions of these. I need to discover specific driving styles in the data I have. For example, drivers who use less some gears, run the engine at higher average torque because they use these gears only on accelerations. Doing that means to evaluate if any relationship/correlation among the shapes of the curves occurs. With scalars, I could compute the Pearson's correlation coefficient to evaluate the degree of linear correlation. But, is there any similar which I may use with trends?