i have this question, wondering if this is the place to ask:
i have a bunch of x-y datasets and want to compare them to a reference set in trellis view. Is there a way to have my reference set show up in all trellis panels without having to actually replicate the data many times? Is there a way to access the function that evaluate trellis location?
To illustrate, an example dataset is as following. I'd want to plot y vs x, trellis by var1, color by var2. Then the question is how to have some points appear on all trellis panels without having to replicate for all values of var1 and var2.