ggbiplot - change the group color and marker

ggbiplot, pca, r

Solution

The following works for me.

ggbiplot(wine.pca, obs.scale = 1, var.scale = 1, group=wine.class,
     varname.size = 3, labels.size=3, ellipse = TRUE, circle = TRUE) +
scale_color_manual(name="Variety", values=c("orange", "purple", "green")) +  
scale_shape_manual(name="Variety", values=c(17:19)) +
geom_point(aes(colour=wine.class, shape=wine.class), size = 3) +
theme(legend.direction ="horizontal", 
      legend.position = "top")

For the legend, the trick seems to be to use the same `name` for `scale_color_manual` and `scale_shape_manual`.

Problem

In the example ggbiplot script plot there are 3 groups, how can I change the marker colors and shapes? ``` library(ggbiplot) data(wine) wine.pca <- prcomp(wine, scale. = TRUE) ggbiplot(wine.pca, obs.scale = 1, var.scale = 1, group=wine.class, varname.size = 3, labels.size=3, ellipse = TRUE, circle = TRUE) + scale_color_discrete(name = '') + geom_point(aes(colour=wine.class), size = 3) + theme(legend.direction ='horizontal', legend.position = 'top') ```

Original source