8 links to BETTER understand principal component analysis (PCA)

9 links to BETTER understand principal component analysis (PCA):

1. https://divingintogeneticsandgenomics.rbind.io/post/pca-in-action/  PCA in action, my blog post to calculate SVD and PCA with #rstats 

2. https://www.youtube.com/watch?v=rYz83XPxiZo MIT 1806 linear algebra  on SVD

3. https://peterbloem.nl/blog/pca-4 THE SINGULAR VALUE DECOMPOSITION (SVD)

4. http://rafalab.github.io/pages/harvardx.html High Dimension data analysis, week 2. 

5. https://towardsdatascience.com/why-pca-looks-triangular-a642daac721a why PCA looks triangular. 

6. https://www.nxn.se/valent/2017/6/12/how-to-read-pca-plots How to read PCA plots for single-cell data.

7. https://twitter.com/AedinCulhane/status/1007110262187544577 PCA horseshoe artifact

8. https://www.youtube.com/watch?v=_UVHneBUBW0  by Josh Starmer