Re: Structures 6.1.1 Basic Usage and Examples

[Julien Bect]

Le 13/05/2014 14:35, Mike Miller a écrit :
> On Tue, May 13, 2014 at 09:52:11 +0200, Andreas Weber wrote:
> > The manual
> > http://www.gnu.org/software/octave/doc/interpreter/Basic-Usage-and-Examples.html#Basic-Usage-and-Examples
> > shows
> >
> > x.a = 1;
> > x.b = [1, 2; 3, 4];
> > x.c = "string";
> > x.b.d = 3;
> > error: invalid assignment to cs-list outside multiple assignment
> >
> > which works in Matlab and since it's in the manual I guess this also
> > worked in octave somewhen prior 3.6.2.
> >
> > I'm not sure if this is related to
> > https://savannah.gnu.org/bugs/?func=detailitem&item_id=32381
> That looks related to me. According to the bug report this worked in
> 3.2 and was changed for 3.4.
>
> Perhaps fix the manual to use either
>
>    x.b = [];
>    x.b.d = 3;
>
> or
>
>    x.b = struct ("d", 3);
>
> instead?

The example from Octave's documentation :

    x.a = 1;
    x.b = [1, 2; 3, 4];
    x.c = "string";
    x.b.d = 3;

runs without even a warning in both Matlab R2012a and Matlab R2013a.

The example from the older bug report :

    x = 1;
    x.a = 2;

also results in overwriting the scalar value 1.0 with a structure, but 
this time with a warning :

    ??? Warning: Struct field assignment overwrites a value with class 
"double".
    See MATLAB 7.0.4 Release Notes, Assigning Nonstructure Variables As 
Structures Displays Warning for details.

I don't know about R2013b or R2014a.

Both examples currently fail in Octave (with a different error, though).

Unless Matlab's behaviour has recently changed, I would say this is a 
bug in the code, not in the documentation.