Session Ready
Exercise

The Kaiser-Guttman rule and the Scree test

In the video, you saw the three most common methods that people utilize to decide the number of principal components to retain:

  1. Kaiser-Guttman rule
  2. Scree test (constructing the screeplot)
  3. Parallel Analysis

Your task now is to apply all of them on the R's built-in airquality dataset!

Instructions
100 XP
  • Create a PCA model using PCA().
  • Apply the Kaiser-Guttman rule using the enhanced version of the summary() function on pca_air asking for 4 dimensions.
  • Construct a screeplot on the PCA object using factoextra and apply the scree test for the first 5 dimensions. In other words, eyeball the sweet spot that creates the elbow decline to decide the number of dimensions to keep.
    Loading