2008/11/2 William Stein <[EMAIL PROTECTED]>:
>
> On Sun, Nov 2, 2008 at 10:57 AM, Robert Dodier <[EMAIL PROTECTED]> wrote:
>> William Stein wrote:
>>
>>> I personally Python well suited to mathematical computation,
>
> Wow, I omitted a lot of words from that sentence.
>
>> No problem with any computation involving literal objects.
>> It's the symbolic stuff that's lacking.
>>
>>> and at least the approach in Python regarding undefined variables
>>> is consistent with every other general purpose programming
>>> language I've ever used.
>>
>> Well, this is an opportunity for Sage to do something usefully
>> different, then.
>
> Sage has done something different, which is to be consistent
> with many mainstream general purpose programming language
> (by which I mean languages such as Java, Python, C#, etc.)
>
>>
>>> But it is definitely different than Mathematica.
>>
>> Apparently Maple also does not require variables to be declared
>> (to judge by their quick start guide). Neither does Maxima/Macsyma
>> nor MuPAD nor PARI/GP ftr.
>
> That's right -- many of the special purposes math languages don't
> require variables to be defined. A notable exception is the Magma
> which requires variables to be define before using them.
>
>>> What is wrong? That statement Justin made or that he made it at all?
>>
>> It's a classic strawman. There's no evidence whatsoever in the
>> original message that the o.p. (Seberino) has assumed that he knows
>> "all there is to know about how to use a Computer Algebra System".
>
> Well just for the record I know the o.p. personally, I he is an
> extremely well intentioned and considerate person, and
> I hope he doesn't take any offense to Justin's
> also (I hope) well meaning remarks.
>
>>> The first line of section 2 of the tutorial (about calculus) is
>>> "The solve function solves equations. To use it, first specify some
>>> variables;
>>> ..." and gives an example of using var.
>>>
>>> I guess this suggests that one needs to use var. This would
>>> be a good place in the tutorial to insert a sentence that if you
>>> don't use var then you will get a NameError, and that this
>>> behavior is different than in Mathematica, and there is no
>>> mode to change this, since it's a basic feature of how the Python
>>> language works.
>>
>> Well, that would be an improvement. The need to declare variables
>> is different from various other packages, not just Mathematica. Some
>> explanation should go in the documentation for var itself as well.
>>
>> FWIW
>
> OK, let's do that.
>
How much of the problem would go away if the standard startup file had
var('a b c d e f g h i j k l m n o p q r s t u v w x y z')
in it? So that var() only had to be used explicitly for longer variable names?
John
> William
>
> >
>
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