R/Stat lm.R

In gfalbery/ggregplot:

# Geom_smooth linear model by Hadley Wickham from official ggplot2 site ####

StatLm <- ggproto("StatLm", Stat, 
                  required_aes = c("x", "y"),
                  
                  compute_group = function(data, scales) {
                    rng <- range(data$x, na.rm = TRUE)
                    grid <- data.frame(x = rng)
                    
                    mod <- lm(y ~ x, data = data)
                    grid$y <- predict(mod, newdata = grid)
                    
                    grid
                  }
)

stat_lm <- function(mapping = NULL, data = NULL, geom = "line",
                    position = "identity", na.rm = FALSE, show.legend = NA, 
                    inherit.aes = TRUE, ...) {
  layer(
    stat = StatLm, data = data, mapping = mapping, geom = geom, 
    position = position, show.legend = show.legend, inherit.aes = inherit.aes,
    params = list(na.rm = na.rm, ...)
  )
}