Robert Dodier wrote:
> On 3/29/09, R Fateman <fateman at cs.berkeley.edu> wrote:
>
>
>> While I agree that Maxima should not ask the sign of an expression when
>> it can be figured out, the problem of ridding the system of these questions
>> when the sign of an expression is NOT apparent cannot be solved by
>> simply forbidding it, or blaming someone.
>>
>
> Are you sure?
yes.
> I'd like to blame the guy who wrote db.lisp.
>
You could call him up or send him email. Professor Genesereth at Stanford.
> What a disaster! It doesn't change anything but now I feel better.
>
You could try replacing db.
>
>> Probably the vast majority of users of Maxima are students, and they use
>> the program for trivial tasks, like calculus homework.
>>
>
> I doubt it, actually. We don't seem to get many undergraduate calculus
> questions.
>
>
Why would a user of Maxima doing calculus problems send you questions?
The track record for my table of integrals lookup program suggests that
out of hundreds of thousands of questions, most of them are
syntactically incorrect, but of those that are valid input, many of them
are sin(x).
>> Since it appears that Sage is an inconvenient front-end to Maxima, the
>> solution is simple. Don't use Sage to access Maxima. Maxima was
>> designed as an interactive program.
>>
>
> The intent of the original developers doesn't matter so much anymore;
> the present situation is that people want to use Maxima as a
> noninteractive computational engine in various contexts.
>
Then complaining about it does not make sense. After all, you could
complain that Microsoft word made a lousy "batch" text editor. But would
anyone listen?
(There are such things as batch editors. An ancient one was "sed")
> Why not make it happen?
When the answer simply cannot be computed from the information
available, you have several options.
1. stop (error?)
2. stop (ask for help?)
3. compute a tree of answers allowing for each possible answer
(potentially infinite if question is "is n>a", "is n>a+1" type of
sequence )
4. give an incomplete answer (like Mathematica)
5. give an answer in a clumsy or possibly wrong form (like Mathematica)
6. weaken your computer algebra system so that no such questions ever
come up. (e.g. most of the programs that Sage calls)
Do you have another way of "making it happen" that I have missed?
> It's not just Sage btw; coping with
> asksign is a problem which has to be solved by every user interface.
>
There is a user interface in Maxima, written in Lisp. It is quite
possible to write an elaborate graphical user interface entirely in
Lisp, as demonstrated by the Lisp Machine version.
People who write a separate interface, generally in another programming
language, do so for a variety of reasons.
At least some of them were written without a clear understanding of
Maxima, and may not work very well for serious users.
Some of them work fine, but generally require some Lisp interface
programming too.
>
>> I know that Robert D. has expressed concern repeatedly about asksign,
>>
>
> Yeah. Just wanted to make sure everyone knows I haven't given up.
>
Well, if you have another idea, please throw it in to the list above!
RJF
> Robert Dodier
>