this toolbox requires
pkg load signal % for xcorr xcorr2 dftmtx etc.
pkg load specfun % for ellipke
pkg load image % for imfilter etc.


note that atan2(-0,-0) gives 0 in matlab and -pi in octave
there is no simple "right" answer:
http://savannah.gnu.org/bugs/?func=detailitem&item_id=37379


% octave bug 39254:

% works fine:
a = single(5 * ones(2,3,4));
b = double(6 * ones(2,3,4));
a .* b

% fails with error
% invalid conversion of ComplexNDArray to ComplexMatrix
c = single(5i * ones(2,3,4));
d = double(6i * ones(2,3,4));
c .* d


Notes circa 2012

To make IRT work cleanly with octave, here were the changes made:

if: short circuit | & to || &&
modify strum methods to return 1 and only 1 output (nicely simplifies anyway).

todo:
fail -> ir_fail because octave has its own fail()
printf -> fprintf (why?)

missing features: zoom colorbar(gca, map)