PCA plot with PC3 and PC4 using ggbiplot

Question

[ukhan]

I need some help to get PC3 and PC4 for my data.

library(ggbiplot) iris<- read.csv("PCA2_umar.csv") log.ir <- log(iris[, 1:8]) ir.species <- iris[, 9]

ir.pca <- prcomplog.ir, center = TRUE, scale. = TRUE)

ggbiplot(ir.pca, obs.scale = 1, var.scale = 1, groups = ir.species, alpha = 0) + theme(legend.direction = 'vertical', legend.position = 'right') + scale_color_manual(values=c("Black", "Black")) +
scale_fill_manual(values = c("#FF8000", "#0080FF")) + # just offset by one to show geom_point(size = 3, shape = 21, aes(fill = groups, color = groups))

PS. Also how can I show the two groups with different symbol. I need to show one of the group with "Dot in a circle" symbol style. Many thanks Link to Excel data

[ukhan]

By including ggbiplot(ir.pca, choices = c(3,4), obs.scale.... we can get PC3 and PC4.