This question already has an answer here:
This is probably a fairly simple question but it occurred to me, when trying to go through some data, that I wasn't sure how.
Say you have some numeric variable vs. arc degrees-- like the price of real estate when looking in any direction. You want to see if there is a quadratic correlation between these two. In other words, the hypothesis is that land is most expensive in one direction, then gets less expensive -180 degrees away.
What's the standard way to treat or transform degrees, i.e. a repeating or circular variable?
There is a somewhat related question here but it also involves other things, and I don't see how the
scale function in R applies here.