I have a short question. I've performed a principal component analysis and obtained two components. Are two components enough two perform a cluster analysis (number of participants > 400)? Thanks for your help!
If the goal is to identify optimal number of clusters from the data, one way is to use Consensus Clustering which performs repeated random sampling on the data, and identifies the number of clusters that has the most robust cluster membership across variables.
To answer your more question more directly, N top components should correspond to 2*N clusters in the linear space as each component represents variables correlated and anti-correlated with it.