Side-by-side plots with ggplot2

Question

I would like to place two plots side by side using the ggplot2 package, i.e. do the equivalent of par(mfrow=c(1,2)).

For example, I would like to have t

Answer 1

Using tidyverse:

x <- rnorm(100)
eps <- rnorm(100,0,.2)
df <- data.frame(x, eps) %>% 
  mutate(p1 = 3*x+eps, p2 = 2*x+eps) %>% 
  tidyr::gather("plot", "value", 3:4) %>% 
  ggplot(aes(x = x , y = value)) + 
    geom_point() + 
    geom_smooth() + 
    facet_wrap(~plot, ncol =2)

df