R: polynomial shortcut notation in nls() formula
With the linear model function lm() polynomial formulas can contain a shortcut notation like this: m <- lm(y ~ poly(x,3)) this is a shortcut that keeps the user from having to create x^2 and x^3 variables or typing them in the formula like I(x^2) + I(x^3). Is there comparable notation for the nonlinear function nls()? ...