Modifying the shape for a subset of points with ggplot2

Question

I\'m attempting to plot a large scatter plot that varies along a large number of dimensions.

Here\'s my starting plot:

 p <- ggplot(mtcars, aes(wt, m         


        

Answer 1

Instead of initially putting your variables within the ggplot function, try to map your variables individually for every layer you add.

p <- ggplot(data = mtcars)+
geom_point(aes(wt, mpg, shape=as.factor(cyl), colour=gear, size=carb))+
geom_point(aes(wt[carb==8], mpg[carb==8]), colour="black", shape=1, size=7)