Multiple plots: oddities (bugs?), missing features in Xmaxima and wxMaxima

----- Original Message -----

> From: Mario Rodriguez <biomates at telefonica.net>
> On 09/17/2011 07:48 AM, Virgil L wrote:
> 
>> 
>>  To make a concrete question: can maxima infer -- in the context of draw2d 
> of course -- that (sin(x),x,0,10) MUST mean? explicit(sin(x),x,0,10) and 
> (y^2=x^3+1,x,-4,-4,y,-4,4) MUST mean? implicit(y^2=x^3+1,x,-4,-4,y,-4,4) ?
>> 
>> 
>>  If true then the declaration explicit/implicit could be _optional_, that 
> is, allowed but not required.
>> 
>>  Of course, if a user wants to declare explicit/implicit for additional 
> clarity, consistency, etc fine....s/he should still be able to do so. But if 
> maxima can infer unambiguously what the user means it would seem helpful to 
> allow maxima to do so. And even if maxima occasionally infers wrong, the user 
> could THEN write the complete declaration (while not writing it the vast 
> majority of the times).
>> 
> Hello,
> 
> You are focusing your attention on the syntax for explicit/implicit, but others 
> have asked, for example, why are we using symbol = for the options. Some people 
> would prefer something like


Hi, Mario:
I think we should not mix up two related but different issues: (1)Choosing the right/best format for plot specifications with (2) eliminating redundant/superfluous entry of information. The implicit/explicit issue falls in category (2), whereas the other issues you mention falls into (1).

There obviously are many, many formatting possibilities, and it is difficult to "prove" that anyone is "superior" to the others. The one possible criterion to choose an "official" format would be to follow plot2d whenever possible, simply because plot2d is the "incumbent" function and I imagine most of us do learn plot2d usage before draw2d. This I discussed in my previous email.

The?implicit/explicit declaration is a totally different concern. The question of whether this declaration is?redundant?CAN be answered objectively, and if the answer is yes, then it would seem?uncontroversial?to make this and any redundant declaration optional.?

To differentiate between an implicit vs explicit declaration, not only is there an equal sign in one case but not in the other. The implicit declaration also involves 2 variables whose ranges are specified, whereas the explicit one only has one. So, it seems that the declaration simply carries no information, that is, it does not tell maxima anything that maxima could not infer easily otherwise.?I haven't thought about the parametric case, but I suspect that it is similar.

It is also relevant that -- as far as I know -- ?the explicit/implicit?declaration is used EVERY time, even in the simplest of all plots, whereas other specifications are only used in certain cases.?

In all, if it can be confirmed that the implicit/explicit/parametric declaration is redundant, then it cannot possibly hurt to make it optional for everybody, without any need for the end user to make a wrapper function.

As for the wrapper functions to simplify data entry, thanks for your tips. I may give them a try. Still, it would be preferable to have one "official" wrapper, for the purpose of collaboration. Perhaps at some point we can start a little project of creating a wrapper that translates plot2d-like calls to draw2d calls whenever possible. But again, this is different from the redundancy issue discussed above.

Best,

Virgil

>