I met a linear algebra problem: Our field is complex number, find the Jordan basis for the matrix $$\begin{pmatrix} 0& 1 & 2&3\\ 0 &0&1&2\\ 0&0&0&1\\ 0&0&0&0\\ \end{pmatrix}$$
I think this problem is related Jordan Canonical Form, but I haven't learnt the term "Jordan basis". What is this? Thank you very much!
Another unrelated question: JCF and the rational form are useless in practice, right? SVD is more useful, right? I saw a lot of applications of SVD, like image compression, PCA, recommender systems, etc. But I have never, never, seen any applications of JCF or the rational form.