[geomark]

I enjoyed this articled called "Principal Components Analysis for Dummies" that illustrates eigenvectors and eigenvalues. https://georgemdallas.wordpress.com/2013/10/30/principal-com...

[steamer25]

There's also this interactive page for eigen- vectors and values: http://setosa.io/ev/eigenvectors-and-eigenvalues/ (as well as a sibling for PCA: http://setosa.io/ev/principal-component-analysis/)