Re: Detecting Matlab or Octave

[John W. Eaton]

On 25-Jul-2002, I wrote:

| [...] you could try something like __OCTAVE_VERSION__,
| which, unlike OCTAVE_VERSION, is supposed to be a constant that can't
| be modified (seems to be broken in 2.1.x, but that should be fixed
| shortly).

Ooops.  I forgot that some time ago, I made a change so that built-in
"constants" could actually be modified, but they would return to their
original value when cleared.

I'm no longer sure what is the better behavior.  So for now at least,
I plan to leave things unchanged.  Octave will allow you to assign
values to these constants, thus shadowing their original values.  You
can clear them to recover the built-in value, but you can't clear the
built-in value.  For example:

  octave2.1:6> __I__    
  __I__ = 0 + 1i
  octave2.1:7> __I__ = 1;
  octave2.1:8> __I__
  __I__ = 1
  octave2.1:9> clear __I__
  octave2.1:10> __I__
  __I__ = 0 + 1i
  octave2.1:11> clear __I__
  octave2.1:12> __I__
  __I__ = 0 + 1i

Does this seem reasonable, or would some other behavior be better?

jwe



-------------------------------------------------------------
Octave is freely available under the terms of the GNU GPL.

Octave's home on the web:  http://www.octave.org
How to fund new projects:  http://www.octave.org/funding.html
Subscription information:  http://www.octave.org/archive.html
-------------------------------------------------------------