__and I have been unable to get any kind of an answer...__One (well three...) is just for my curiosity (below), the other I will ask if our lil ol PMBug.com forum responds positively...

1) Regarding square matrices (linear algebra), I know there are plenty of applications for two-dimensional ones, I use such applications about once every month or two (in statistical analysis of our bearing company sales). My question is:

**are there any applications for three-dimensional (and by extension, higher order) matrices?**And how would one go about making the relevant calculations (the equivalent of determinants, eigenvalues and eigenvectors)? Are there any textbooks on this?

Thanks! I am kind-of amazed that the idea of three dimensional matrices has mystified so many people, this is the first "math thing" I have looked into that

**no one**has (yet) been able to help me with or even know anything about it.