Re: creating another object of a given class

[Jaroslav Hajek]

On Thu, Dec 23, 2010 at 12:11 AM, Steve White <address@hidden> wrote:
>
> What is the best way to create another object of a given class?
>
> Say a function takes an object as an argument
> and a new object of that class is needed.
>
> One way to do it (for an object 'obj') is
>
>     name = class (obj);
>     new_obj = feval (name, args);
>
> However, the Coding-Tips documentation entry says to avoid calling
> feval "excessively":
> http://www.gnu.org/software/octave/doc/interpreter/Coding-Tips.html#Coding-Tips
>
> Another option would be to attach a function handle to the
> constructor of each class as an object member, and call that
> when needed.  But this seems cludgy.
>
> Is there a better/faster/accepted way to do this?
>

Oh no, this is entirely OK. You can interpret that advice as "use
handles where possible and call the directly if possible". There is
little to worry here, however. Besides, the classes internals are not
remotely that tightly optimized to make name lookup a bottleneck :-/