Again $table function, speed/functionality improved

On 13. May, 2009, at 6:41 PM, Robert Dodier wrote:

> On Wed, May 13, 2009 at 7:09 AM, ?iga Lenar?i?  
> <ziga.lenarcic at gmail.com> wrote:
>
>> Any comments on $table implementation? Any comments on the  
>> function name?
>> Anything needs changing before this gets into Maxima?
>
> I'm not 100% sure we want to import "table", and I'm not in a hurry
> to come to a decision. That said, I'd be more interested if we can
> replace makelist and create_list. It would be nice to have a more
> extensive list-making function, but I don't like having a multitude of
> functions which do similar things.

I understand your concern (even right now, we have create_list and  
makelist)...
One idea I had is, table could be called makelist - it is not hard to  
recognise if it is a $makelist call or $table call if you look at the  
arguments. The most simple method would be to look at second  
argument, and if it's a list call $table internally, if it is not a  
list, call the old $makelist. This can get messy though!

Otherwise building upon current $makelist and $create_list is not  
wise in my opinion - the calling sequence of makelist(expr, var,  
start, end); can not be extended into something as flexible as $table  
offers.

Table can be a replacement for these two, which cannot be changed  
without breaking compatibility with existing programs (or can they?).  
In documentation there could be a note that one should rather use  
table than makelist and create_list and eventually they could be  
removed... (that's my most realistic view of solving this  
makelist,create_list,table mess)..

Ofcourse there's no hurry to put $table in, but I think many people  
would benefit if it appeared in the next version in some form...

> "tabulate" is a better name, I think --- it is an imperative
> like makelist or create_list (or expand, subst, etc).
Probably the most important thing in the end is that the name is  
short :), not cryptic and easy to remember.. something with lists  
would be nice.. I like the fact that 'table' is shorter than  
'makelist', but I don't like the fact that the name is stolen from  
Mathematica and has nothing to do with lists.

>> A similar function could be written for arrays - if Maxima ever  
>> gets a
>> better array support (like amatrix package).
>
> Well, I wouldn't bother trying to wedge array stuff into "table" at  
> this point.
> Maxima generally doesn't know what to do with arrays as it stands.
> I think it would be better to come up with a plan to improve array
> stuff across the board.
I agree - it would be very nice if Maxima's support for arrays would  
improve... in ideal case they shouldn't be harder to use than lists.


> FWIW
>
> Robert Dodier

Regards,
Ziga Lenarcic