Suppress geom_smooth() using formula 'y ~ x' messages in ggscatter()

[dchiu911]

I think we can suppress the persistent

 `geom_smooth()` using formula 'y ~ x'

messages (from ggscatter() for e.g.) by adding the following after this line:

option[["formula"]] <- y ~ x

[aphalo]

@dchiu911 The behaviour of geom_smooth() depends on the number of observations. Probably it would be best to set method = lm to avoid it switching to using splines. Anyway, there have been no commits at this repo for 2 years and no answers from the repo owner to issues raised or pull requests also for a very long time. I think the effort of learning the Grammar of Graphics and using 'ggplot2' and its extenssions through this grammar avoids many of the headaches caused by "canned" plotting functions like those in 'ggpubr'.