"Error: Continuous value supplied to discrete scale" in default data set example mtcars and ggplot2

Yeah, I was able to fix it by converting the color and shape aesthetics to factors:

ggplot(mtcars, aes(x=wt, y=mpg, color=as.factor(cyl), shape=as.factor(cyl))) +
  geom_point() + 
  geom_smooth(method=lm, se=FALSE, fullrange=TRUE)+
  scale_shape_manual(values=c(3, 16, 17))+ 
  scale_color_manual(values=c('#999999','#E69F00', '#56B4E9'))+
  theme(legend.position="top")

as.factor makes it work

ggplot(mtcars, aes(x=wt, y=mpg, color=as.factor(cyl), shape=as.factor(cyl))) +
  geom_point() + 
  geom_smooth(method=lm, se=FALSE, fullrange=TRUE)+
  scale_shape_manual(values=c(3, 16, 17))+ 
  scale_color_manual(values=c('#999999','#E69F00', '#56B4E9'))+
  theme(legend.position="top")

Tags:

Colors

R

Scatter Plot

Ggplot2

Scatter

Related