Re: signbit and logical tests

[John W. Eaton]

On 02/09/2013 09:02 PM, Michael D. Godfrey wrote:
> I looked a bit more at the "logical" tests as described in Sections 4.6-8.
> If signbit() returned a logical it would fit with "isxxxx" functions and
> make more
> sense. Referencing Section 4.6 through 4.8 in the signbit() documentation
> would then make this all fit together and more understandable.
>
> Is this a useful idea?

The signbit function in Octave is just a simple wrapper around the 
system library signbit function, and that returns the value of the sign 
bit as an integer.  I don't know whether it would be a good idea to 
change that definition for Octave.  The other function that I know of in 
Matlab that returns something different from what the C library function 
returns is strcmp.  So there is precedent for that kind of thing.  Or, 
if you want a predicate-style function, maybe we should have isnegative 
instead?

jwe