Re: zplane does not return vectors of handles

[Nicholas Jankowski]

I have found a discrepancy between the matlab specification and
the octave implementation of the zplane function, found in the signal
package.

The octave implementation does not give any output values, but matlab does:
/[hz,hp,ht] = zplane(___) returns vectors of handles to the zero lines, hz,
and the pole lines, hp.
ht is a vector of handles to the axes/unit circle line and to text objects,
 which are present when there are multiple zeros or poles./
( https://se.mathworks.com/help/signal/ref/zplane.html#d120e189724
<https://se.mathworks.com/help/signal/ref/zplane.html#d120e189724>  )

I recommend filing an incompatibility bug report at bugs.octave.org  (use the top menu Bugs/Submit New)