Re: numel(foo{:}) - feature or bug ?

[Marco atzeri]

On 8/6/2011 3:44 PM, Ben Abbott wrote:


>  From my reading of the discussion, I'm skeptical that everyone understands 
> that foo{:} is a cs-list, or maybe don't understand cs-lists? Consider the 
> short example below ...

Calling it "comma separated list" is probably more clear. (IMHO)
Thanks for the clarification in any case.

>         clear a
>         foo = {"a", "ab", "abc", [1:4;5:8;9:12]};
>         a(1).args = foo{1};
>         a(2).args = foo{2};
>         a(3).args = foo{3}
>         a(4).args = char(foo{4});
>         numel (a.args)
>         ans = 72
>         numel (foo{:})
>         ans = 72
>         numel (foo{1}, foo{2}, foo{3}, foo{4})
>         ans =  72
>
> Both foo{:} and a.args produce cs-lists (I added the char() function to avoid a 
> syntax error).
>
> Ben

I found very un-intuitive that the order matters a lot

        numel (foo{1}, foo{2}, foo{3}, foo{4})
        ans =  72
        numel (foo{2}, foo{3}, foo{4},foo{1})
        ans =  36
        numel (foo{3}, foo{4},foo{1},foo{2})
        numel (foo{4},foo{1},foo{2},foo{3})
        ans =  6

specially if one of the element is empty

        foo{1}=[]

        numel (foo{4},foo{1},foo{2},foo{3})
        ans = 0
        numel (foo{3}, foo{4},foo{1},foo{2})
        ans = 0
        numel (foo{2}, foo{3}, foo{4},foo{1})
        ans = 0
        numel (foo{1}, foo{2}, foo{3}, foo{4})
        ans =  72


but this is coming from the definition.
I wonder of the real usage of numel applied to a cs-list.

Marco