ggplot remove or replace the 'a' in geom_text legends

Question

I trying to remove the little a in front of a legend but without any luck. Other possibility would be to create a legend or legend like text next to the graph but I am running out of ideas. Maybe someone can help me.

I plot on specific positions a red X and I want to point out, that the X marked things are imputed...

df <- data.frame(x=rnorm(10),y=rnorm(10))
ggplot(df, aes(x=x, y=y)) + geom_point() + geom_text(aes(x=0,y=0, color=factor(1)), label='X') +  
  scale_color_manual(values = 'red', name='imputed',labels='imputed') +
  theme(legend.key=element_blank(), legend.title=element_blank())

I think the best result would be to replace the little a by a X. But I could not find any solution for it.

Answer 1

The problem is that you use geom_text to draw the cross.

A simple way to solve it is to use geom_point to plot the cross:

ggplot(df, aes(x=x, y=y)) + geom_point() + geom_point(aes(x=0,y=0, color=factor(1)), shape='X', size=5) +  

scale_color_manual(values = 'red',labels='imputed') +

theme(legend.key=element_blank(), legend.title=element_blank())