title: How to create a legend across two different types of geoms ggplot2
body: <p>I have two different datasets which I'd like to plot in the same ggplot2 plot, using different geoms for each. Ideally I would also like a legend which shows that the point geom corresponds to one type of data and the line geom corresponds to the other, but I cannot figure out how to do this. An example of what my data basically looks like is below, minus the legend.</p>
  <pre><code>require(ggplot2)
  
  set.seed(1)
  
  d1 = data.frame(y_values = rnorm(21), x_values = 1:21, factor_values = as.factor(sample(1:3, 21, replace=T)))
  d2 = data.frame(y_values = seq(-1,1,by = .05), x_values = seq(1,21,by = .5))
  
  
  
  ggplot() + 
  geom_point(data=d1, aes(x=x_values, y=y_values, color=factor_values)) + 
  geom_line(data=d2, aes(x = x_values, y=y_values), color=&quot;blue&quot;)
  </code></pre>