Why does the output for polynomials based on the function poly() with raw = TRUE not match the output of raw polynomials (I())
I am curious why the two versions of my regression model in R give different results for the quadratic term. If I have understood correctly, using the function poly(x,2,raw=TRUE) should give the same result as the use of raw polynomials based on I(x^2). What could be the reason that this is not the case for me?