Remove lines from color and fill legends

19
votes

I have a plot with three different legends: one for linetype, one for color, and one for fill. In the color and fill legends there are also some lines which I wish to remove, but how?

Here is some example code:

# some data
hline_df <- data.frame(name = c('a', 'b'), y = c(1, 2))
df <- data.frame(x = c(1, 2), y = c(0.5, 1.5), con = c('a', 'b'), col = c('d', 'e'))

# the plot
ggplot(df, aes(x, y, fill = con)) +
  geom_bar(stat = 'identity') + 
  geom_point(aes(color = col)) +
  geom_hline(data = hline_df, aes(yintercept = y, linetype = name),
             color = 'red', show_guide = TRUE)

enter image description here

I get the "name" guide for both red lines, that is fine.
The "col" guide has red lines crossing the dots, I want to remove them!
The "con" guide also has red lines which should be removed.

I could modify parts of the legend with 

guides(fill = guide_legend(override.aes = list(colour = NULL)),
       color = guide_legend(override.aes = list(colour = NULL)))

This removes the colour, but the lines are still there.

Thanks in advance!

3
rggplot2colorslegend
Hm, rearranging to ggplot(df, aes(x,y,fill=con)) + geom_hline(data=hline_df,aes(yintercept=y,linetype=name), color='red',show_guide=TRUE) + geom_point(aes(color=col)) + geom_bar(stat='identity') + geom_hline(data=hline_df,aes(yintercept=y,linetype=name), color='red',show_guide=F) seems to work for con but the red line is still in col. And to be honest, I don't understand, why it is working :-) – drmariod
Ahhh, I tried to set linetype=NULL and this didn't worked as expected... Also the trick with plotting the hline two times, on in the back and one in the front is great! Would you like to post an answer, so I can mark it as fixed? – drmariod

3 Answers

27
votes

You may set linetype = 0 or "blank" (on different linetypes here) for the filland color guides in your override.aes call.

Also note that I moved the fill aes from the 'top level' in ggplot to geom_bar.

ggplot(df, aes(x, y)) +
  geom_bar(aes(fill = con), stat = 'identity') + 
  geom_point(aes(color = col)) +
  geom_hline(data = hline_df, aes(yintercept = y, linetype = name), color = 'red', show_guide = TRUE) +
  guides(fill = guide_legend(override.aes = list(linetype = 0)),
         color = guide_legend(override.aes = list(linetype = 0)))

enter image description here

4
votes

As suggested by user20650

ggplot(df, aes(x,y)) + 
  geom_hline(data=hline_df,aes(yintercept=y,linetype=name), color='red',show_guide=TRUE) + 
  geom_point(aes(color=col), size=5) + 
  geom_bar(aes(fill=con), stat='identity') + 
  geom_hline(data=hline_df,aes(yintercept=y,linetype=name), color='red',show_guide=F) + 
  guides(color = guide_legend(override.aes = list(linetype = 0)))

So the first geom_hline creates the legend but the line is behind the bars...
the second call brings the line in front of the bars but does not print a legend (great idea).
The las guide is overwriting the aesthetics line type with 0... In this way it removes the line from the legends... I tried with NULL but this didn't worked before...

Thanks again.

enter image description here

3
votes

Using:

ggplot(df, aes(x,y,fill=con)) + geom_bar(stat='identity') + 
  geom_point(aes(color=col)) +
  geom_hline(data=hline_df,aes(yintercept=y,linetype=name),color='red',show_guide=FALSE) +
  guides(linetype=FALSE,color=FALSE)

gives me this plot: enter image description here