title: Control legends in ggplot with geom_bar and geom_point
body: <p>I'm plotting a bar graph and a line/point graph on the same plot and I'm trying to have two legends, one for the points and one for the bars.</p>
  
  <p>However, I end up with 3 legends (instead of two) and the legend for the bars has points in it. Can you help me? Here is a MWE </p>
  
  <pre><code>library("ggplot2")
  
  df2 &lt;- data.frame(Height=rep(c("low", "high"), each=3),
                    Month=rep(c("Jan", "Feb", "March"),2),
                    Trial =c(7, 4, 10, 2, 4, 12),
                    Success = c(2, 2, 7, 1, 3,  8))
  
  
  ggplot(data=df2, aes(x=Month, y= Success, fill= Height)) +
    ggtitle("Title") +
    geom_bar(stat="identity", position=position_dodge()) +
    geom_line(aes(x=Month, y=Success/Trial*max(Success), group = Height, linetype = Height, colour = Height) , size = 3, alpha = 0.7) +
    geom_point(aes(x=Month, y=Success/Trial*max(Success), colour = Height), size = 11) +
    geom_text(aes(label=round(Success/Trial,2), x=Month, y=Success/Trial*max(Success)), color="white", size=3.5, fontface = "bold") +
    scale_y_continuous(sec.axis = sec_axis(~. *1/max(df2$Success) , name="Proporion of success")) +
    labs(x = "Month", y="#Success", fill = "Number of Success", colour = "Proportion of success") +
    scale_colour_manual(values=c('#909999','#E69000'))+
    scale_fill_manual(values=c('#099999','#069F00'))
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/7MZeP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/7MZeP.png" alt="output image"></a></p>
  
  <p>I tried using different versions of <code>guides(colour = FALSE, group = FALSE, fill = FALSE)</code> but with no success. I want to remove the "Height" legend, and remove the big black dots in the "Number of success" legend.</p>