How to change symbols of points for PCA ggplot?

Question

biplot<-ggbiplot(pcobj = PCA,choices= c(1,2),scale = 1,groups = Fdata$Tissue,ellipse = TRUE)+ 
geom_vline(xintercept = 0, linetype = 3)+geom_hline(yintercept = 0, linetype = 3)         

  

Answer 1

try add geom_point(aes(shape=factor(something))). For an example of iris data,

library(ggbiplot)

ir.pca <- prcomp(iris[,1:4], center = TRUE,scale. = TRUE) 

ggbiplot(ir.pca, obs.scale = 1, var.scale = 1,groups = iris$Species, ellipse = TRUE)+geom_point(aes(shape=factor(iris$Species)))

ggbiplot(ir.pca, obs.scale = 1, var.scale = 1,groups = iris$Species, ellipse = TRUE, labels = )+
  geom_point(aes(shape=factor(iris$Species))) +
  guides(color = "none", shape = guide_legend(title = "New"))  +
  scale_shape_discrete(labels = c("a", "b", "c"))