I have three bivariate data sets of different sizes and the same sampling interval. These represent the variation of dry river bed direction with distance at equidistant sample points. When plotted there are clear similarities between the datasets, the bends and their change in direction occur in the same order and magnitude, but some are delayed. I need to prove their equivalence in shape, I have considered co variance but what degree of matching can be demonstrated ? or I could correlate (?) data across the data sets to show equivalence but how to handle the differences in sample number and feature delay? I would appreciate some guidance please.