What type of statistical test can I use to look at the influence of a factor on a frequency distribution (distance) I'm trying to work out what test to use to see whether a factor (presence vs absence) affects a frequency distribution with distance as a predictor.
Just wondering if anyone knows what the best test would be for this
My hypothesis is that the presence of a factor - as an example lets say the presence of a tree canopy will influence the frequency distribution - for example below


I would think about selecting a limited number of most interesting distances, randomly(!) selecting several measurement points and sources of the signal (with and without trees between them), and then running a two-way ANOVA (where one category is the presence of trees, and the other is the distance, which is a discrete variable).
If the relationship between the signal and distance had been linear in all cases, you'd have had an option of using ANCOVA as well, leaving the distance not discrete.
