Umegaki's relative entropy

The command ``REnt'' calculates the Umegaki relative entropy of a matrix $A$ with respect to a matrix $B$,

$$S(A\Vert B)=\mathrm{Tr}(A\log_2 \frac{A}{B}).$$ (17)

$A$ and $B$ are read from the two matrix files fileA and fileB saved by the ``msave'' command (or ``RDOsave'' etc.).

REnt(fileA, fileB);