I've been playing with matlab, and I'm liking it... the built in
documentation on the language is actually excellent, and the language
itself is pretty clean if you're used to java/c/algol type languages.
I like especially the built in syntax for matrix and tensor
operations, and the fact that operations corresponding to the various
special syntaxes are just overrideable methods. But yes, from basic
grammar to the fine points of matrix syntax, the built in help desk is
the best place to start research, I think you might be surprised by
how well written and organized things are; the must have spent mad
cash on that.
As for clojure with matlab, you can compile java classes from matlab
and use those in your clojure code, and similarly, java classes can be
interfaced inside m-files. There's a useful tutorial on the first part
which I followed and it was neat to see my clojure code spitting out
1000x1000 magic squares, but I haven't taken it further.
You might look at Octave, which is an open source clone of matlab, but
with nothing like simulink :/ . Still, for pretty involved number
crunching and plotting, Octave can do what matlab can, and its
language is similar (it might try to actually be compatible with m-
files - I'm not sure about this). Anyways, there might be more free
books about octave :)