Non-graphical linearity estimation
- by aL3xa
In my previous post, I was looking for correlation ratio (η or η2) routines in R. I was surprised by the fact that no one uses η for linearity checking in the GLM procedures.
Let's start form a simple example: how do you check linearity of bivariate correlation? Solely with scatterplot?
There are several ways of doing this, one way is to compare linear and non-linear model R2, then to apply F test to seek for significant difference between them.
Finally, the question is: How do you check linearity, the "non-grafical" way?