Thank you for your fast reply 👍

I see your point regarding more than two dimensions.  In general, I think there is not much argument against supporting higher dimensions?!

My only two concerns are that Matlab does not do it (there were often cases, when drifting away from Matlab, then the next bug report is about to pop up soon) and it might make the code much simpler (without for loops).

If you reduce your code to two dimensions, I will push your function after some small polishing.  If you like to leave it with higher dimensions, I need to think a little more if it makes sense or if there are potential pitfalls.

Thanks for the quick feedback.

I noticed that I'd misread the Matlab documentation:  The inputs need to be given as [M,N].  I've fixed this in the attached file (v2).

Style fixes:

- [ ] No use of `end`, use `endif`, etc.
  DONE
- [ ] No use of `~=`, use `!=`
  DONE
- [ ] No more than 79 chars per line
  DONE
- [ ] Leave a space between variables and operators
  DONE - With the exception of one use of max() within a list.  Adding a space there would result in an error.
- [ ] Adapt docstring to latest standards
  OPEN - Not sure what's needed here.  I don't have any good examples to add to show the use of the function.  (I wrote it to make some old code work that was originally written for Matlab, but its use of freqspace was very basic.)

General necessities:

- [ ] No tests (BIST)
  DONE - Added some basic tests.  Not exhaustive though.
- [ ] No Mercurial patch (NEWS entry, module.mk entries, etc.)
  OPEN - Not sure what's needed here.

General questions:

- [ ] Do you want to be publicly listed as Octave contributor?
  I'm already listed (from a few contributions many years ago).
- [ ] Matlab offers only support for two 2D outputs, your function seems to be N-dimensional.  Are there real use cases justifying the more complicated code?
  Don't know.  In my use-case I only need 1-D functionality.  If it needs to be restricted to 2-D then applying a check on the number of input/output arguments would be an easy way to limit it, but would allow a user to edit the m-file to restore N-D functionality very easily if they wanted.
(I tend to work with 3-D / 4-D (i.e. time varying) medical images, and I've sometimes found it frustrating if functions are limited to 2-D.  So I usually try to write N-D code where it makes sense, even if I'm not aware of a use-case at the time.)

(file #49879)

The Matlab function 'freqspace' is missing from Octave (as of 5.2.0).  I've written and attached an m-file which implements it.  I needed to write it for my own use, so here it is since it might help fill a gap.

As far as I can tell, it includes all the functionality described in the Matlab documentation.