d = sort(rexp(100, rate = 1), decreasing=T)
ggplot(NULL, aes(1:length(d), d)) + geom_point() + scale_y_log10() + geom_smooth(method = lm, se=F)

library(ggplot2)
set.seed(1)
d <-  sort(rexp(100, rate = 1), decreasing=T)
gg <- data.frame(x=1:length(d),y=d
                 )
ggplot(gg, aes(x,y)) +
  geom_point() +
  scale_y_log10() +
  geom_smooth(data=gg[gg$x>11 & gg$x<81,],method = lm, se=F)

# Adding "volume" to the diamonds data frame.
diamonds$volume = diamonds$x * diamonds$y * diamonds$z

ggplot(aes(x = volume, y = price), data = subset(diamonds, volume != 0 & volume < 800)) +
  geom_point(alpha = 1/50, color = '#7ea4b3') +
  geom_smooth(method = 'lm')

ggplot(aes(x = volume, y = price), data = subset(diamonds, volume != 0 & volume < 800)) +
  geom_point(alpha = 1/50, color = '#7ea4b3') +
  geom_smooth(data = subset(diamonds, volume > 0 & volume < 600),
              method = 'lm')