rm(list=ls())
library(LalRUtils)
load_or_install(c('tidyverse', 'data.table', 'magrittr',
  'factoextra'))
nrow = 1e3

df <- data.frame(
    x = rnorm(nrow),
    y = runif(nrow),
    z = runif(nrow)
  )

pc <- prcomp(df, scale = F)

pc %>% str
#%%

data(decathlon2)
decathlon2.active <- decathlon2[1:23, 1:10]
head(decathlon2.active[, 1:6])

res.pca <- prcomp(decathlon2.active, scale = TRUE)

res.pca

#%%
fviz_pca_ind(res.pca,
             col.ind = "cos2", # Color by the quality of representation
             gradient.cols = c("#00AFBB", "#E7B800", "#FC4E07"),
             repel = TRUE     # Avoid text overlapping
             )

#%%
fviz_pca_var(res.pca,
             col.var = "contrib", # Color by contributions to the PC
             gradient.cols = c("#00AFBB", "#E7B800", "#FC4E07"),
             repel = TRUE     # Avoid text overlapping
             )
#%%