Re: Calling a method of an object?

[Robert T. Short]

On 10/18/2012 12:15 PM, Joanna Rutkowska wrote:
> On 10/18/12 21:00, Hoeltgen Laurent wrote:
> > 2012/10/18 Joanna Rutkowska <address@hidden 
> > <mailto:address@hidden>>
> >
> >     Hello, I've created a simple class:
> >
> >     function m = motor (name, Kv, Rm, I0)
> >     m.name <http://m.name> = name;
> >              m.Kv = Kv;
> >              m.Rm = Rm;
> >              m.I0 = I0;
> >              m = class (m, "motor");
> >     end
> >
> >     ...and one simple method:
> >
> >     function power = power_out (motor, u, i)
> >              power = (u - i*motor.Rm) * (i - motor.I0);
> >     end
> >
> >     ... and I created an object of the class motor:
> >
> >     octave:1> m1 = motor ("Sample motor", 400, 0.05, 1);
> >
> >     ... but I cannot call the power_out method using the traditional "OO
> >     way":
> >
> >     octave:2> m1.power_out (1,1);
> >     error: invalid index for class
> >
> >     ... only this form seems to work:
> >
> >     octave:2> power_out (m1, 1, 1);
> >
> >     Is it how this is supposed to be in Octave? The object.method()
> >     calling convention is much more intuitive and more readable than
> >     method(object) IMHO. Also, it clearly allows to avoid name conflicts
> >     if I got some global function or another method with the same 
> > name...
> >
> >     Thanks,
> >     joanna.
> >     _________________________________________________
> >     Help-octave mailing list
> >     address@hidden <mailto:address@hidden>
> >     https://mailman.cae.wisc.edu/__listinfo/help-octave
> >     <https://mailman.cae.wisc.edu/listinfo/help-octave>
> >
> >
> >
> > Hi,
> >
> > according to
> > http://www.gnu.org/software/octave/doc/interpreter/Creating-a-Class.html#Creating-a-Class, 
> >
> > all class definitions must be inside folders starting with an @ symbol.
> > Did you do that?
> Yes, I did:
>
> address@hidden @motor]$ pwd
> /rw/home/user/multirotor_tools/@motor
> address@hidden @motor]$ ll
> total 16
> -rw-rw-r-- 1 user user 142 Oct 18 18:45 display.m
> -rw-rw-r-- 1 user user 119 Oct 18 18:51 get.m
> -rw-rw-r-- 1 user user 181 Oct 18 18:45 motor.m
> -rw-rw-r-- 1 user user 171 Oct 18 21:14 power_out.m
>
> joanna.
>
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It may be clunky, but it is MATLAB syntax.  Since octave attempts to be 
MATLAB compatible we are stuck with it.

So you have to use the documented syntax:

m = motor(...)
p = power(m, ...)

Bob