important for OF maintainer - ismatrix backwards incompatible change in octave 4.0

[Carnë Draug]

Hi

the ismatrix function in Octave will change for the new version 4.0.
Currently, this function returns true if it is a numeric, logical, or
character array with any number of dimensions.  The new version will
return true if the object has two dimensions even if it is a cell or
struct array.

    WARNING: ismatrix() will return true for a struct and false for
            ND numeric arrays.

I quickly grepped Octave Forge for ismatrix and it is used in most of the
packages.  Would be nice if this is fixed in the packages and there were
new released of them before Octave 4.0.

A full replacement / fix would be replacing all current ismatrix() with
"isnumeric (x) || islogical (x) || ischar (x)".  More details on the bug
report [1] and cset [2].

This change is because Matlab added the ismatrix() function in their 2010b
release.  I guess they either forgot to check if we had already implemented
it or screwed up their Octave compatible implementation.

Carnë

[1] https://savannah.gnu.org/bugs/index.php?42422
[2] http://hg.savannah.gnu.org/hgweb/octave/rev/00e31f316a3a