Rather than edit the following SVD posts – unless I __have__ to – let me put some prefatory material here. I am also going to answer a couple of email questions in comments, partly just to check out their mechanics.

The following posts in the math SVD category should be read in the order displayed, not starting from the back.

That may have been a bad idea on my part, but let’s see how it works out. The difficulty is that most of what I do out here will be available in the usual blog-order, latest first. Eventually it may be awkward if one category is in reverse order wrt everything else.

I would like to add two pieces of vocabulary. For the SVD the columns of u and v are called the **left singular vectors of X** and the **right singular vectors of X**, respectively.

I have also discovered that the latex interpreter works in comments. Cool! My understanding is that it does not work in forums; they would be the appropriate place to post code – and have it display as code! After all, that’s where I found the key starting points for latex.