How to change loading labels of biplot in r?

Question

I am struggling with changing the loading labels of biplot. I used prcomp function to run PCA and ggbiplot. I've tried to change it with loading.label.label = c("a","b","c","d") , but it didn't work. I have attached my code and plot below.

k <- kmeans(comp,2)

TW$Group <- factor(k$cluster)

pca2 <- prcomp(TW[,c(7,11,18,19)], center = TRUE, scale. = TRUE)

summary(pca2)

pca2

cc <- c("a","b","c","d")

library(ggbiplot)

p <- ggbiplot(pca2, group = TW$Group, ellipse = TRUE,loadings.label.repel = TRUE) +
  ggrepel::geom_text_repel(aes(colour = TW$Group, label = paste(TW$P,TW$Box)), size = 2.5)+ 
  theme_minimal() +
  xlim(-2.5,2.5) + ylim(-2.5,3.5) + theme(legend.position = c(0.9, 0.9))

plot(p)

Answer 1

Not sure you can do this with the ggbiplot function. A workaround would be to change the names in the pca object like this:

library(ggbiplot)
data(wine)
wine.pca <- prcomp(wine, scale. = TRUE)

rownames(wine.pca$rotation) <- rep("my_names", length(wine.pca$center))
print(ggbiplot(wine.pca, obs.scale = 1, var.scale = 1, groups = wine.class, ellipse = TRUE, circle = TRUE))