Re: turning "Octave:broadcast" warning off by default

[Philip Nienhuis]

Jordi Gutiérrez Hermoso wrote:
> On Thu, 2015-02-19 at 19:57 +0100, Philip Nienhuis wrote:
> > IIRC the warning is also there because Octave strives for Matlab
> > compatibility. Automatic broadcasting isn't ML-compatible AFAIK.
>
> I always take "Matlab-compatible" to mean, "if it works in Matlab, it works in
> Octave". I don't usually take it to mean "if it breaks in Matlab it
> must also break in Octave".

If Matlab code gets run in Octave and then is subject to automatic 
broadcasting, it may "work" (in the sense of "runs w/o error messages) 
but there's no guarantee it'll yield the same (correct or not) results 
as in Matlab. Right?
So some info there might still be useful for unwary users that expect ML 
code to run identically as in Matlab.

That's about as much as I meant to say.

> I get impatient when people want "Matlab-compatible" to mean "exactly
> like Matlab, no worse, and certainly no better".

? Hopefully you're not pointing at me here?
No worries, I'm someone who sometimes thinks that Octave gets too 
ML-compatible.

> As to turning off the warning by default, I don't think it's
> widespread and accepted enough in our corner of scientific computing
> (i.e. the Matlab side, as opposed to the R or Python or Julia side),
> for most people to be used to it. And it's a very surprising behaviour
> for many seasoned Matlab users who expect an error message there.

Exactly.

> If Octave ever becomes dominant enough for most people to find
> broadcasting natural, we should disable the warning. I wish we could
> phrase it in a different way so it doesn't sound like the user did
> something incorrect, but some sort of warning should stay.

Yeah, "warning" is too heavy.

Maybe we should have something like "informative" messages.
The ancient F77 compiler I used to work with on CDC mainframes in the 
80's had such a message type (IIRC it had "informative", "warning", 
"fatal" and "catastrophic" errors :-)  and I may have forgotten one).

Philip