I don't have MATLAB on the system I'm on at the moment but trying your
(slightly modified) example with octave instead works:
#+begin_src org
,#+BEGIN_SRC octave :results output
pkg load symbolic
syms a b
A=[a,b;b,a]
eig(A)
,#+END_SRC
,#+results:
,#+begin_example
OctSymPy v2.2.4: this is free software without warranty, see source.
Initializing communication with SymPy using a popen2() pipe.
Some output from the Python subprocess (pid 28058) might appear next.
OctSymPy: Communication established. SymPy v0.7.6.1.
A = (sym 2×2 matrix)
⎡a b⎤
⎢ ⎥
⎣b a⎦
ans = (sym 2×1 matrix)
⎡ ____⎤
⎢ ╱ 2 ⎥
⎢a - ╲╱ b ⎥
⎢ ⎥
⎢ ____⎥
⎢ ╱ 2 ⎥
⎣a + ╲╱ b ⎦
,#+end_example
#+end_src
I don't know if this helps you at all and/or whether the issue is with
MATLAB...
--
: Eric S Fraga (0xFFFCF67D), Emacs 25.0.92.1, Org release_8.3.4-668-g809a83
