ggplot2: Change legend symbol
Starting in ggplot2_3.2.0, you can choose which glyph you want displayed in the legend keys using the key_glyph
argument in the geom_*()
.
For example, you want to use rectangles instead of lines as your glyph. In that case you can do
df = data.frame(x = rep(1:5, each=3),
y = 1:15,
group = rep(c("A", "B", "C"), each=5))
ggplot(df, aes(x, y, color=group) )+
geom_line(key_glyph = "rect")
See ?draw_key
for a list of the current glyphs available.
You can use function guides()
and then with argument override.aes=
set line size=
(width) to some large value. To remove the grey area around the legend keys set fill=NA
for legend.key=
inside theme()
.
df<-data.frame(x=rep(1:5,each=3),y=1:15,group=rep(c("A","B","C"),each=5))
ggplot(df,aes(x,y,color=group,fill=group))+geom_line()+
guides(colour = guide_legend(override.aes = list(size = 10)))+
theme(legend.key=element_rect(fill=NA))