Bobby Moretti wrote:
>>> These are all good reasons... I wish there was a better way than
>>> having a predefined list of indeterminates... I could see all sorts of
>>> things being screwed up that way.
>>>
>> Such as?
>>
It's easy to imagine things that can go wrong since this is essentially
what Maple (and Reduce/the TI92) does
and I have lots of experience with students doing Maple worksheets in a
computer lab.
The problem is to make sure that they can be easily fixed. For example,
if you want a function to be defined
this way:
f = exp(x)*sin(exp(x))
a student will want f(1) to work. Will it? I'm guessing you'll have a
function like
value(f,1) or subs(1,f)
or somethign like that. This is awkward at first for them but if it is
explained they will get used to it.
What if they want the floating point approximation to 3 decimal places?
Maybe
value(f,1.0)
or something? Again, it must be explained. I can easily imagine a
student setting x = 1 for
some reason and then having the rest of the session messed up since x is
no longer available to
them to define functions with. The student will need a command to
"clear" some of all
predefined variables (such as clear("x") or clear_all() or something
like that).
One idea, which I think students will accept, is to have a command like
load_calculus()
or something. This could for example
(a) load predefined variables,
(b) spit out a very brief screen of explanations (perhaps a list of some
available
commands, an explanation of how to get help in the notebook or on the
command-line, ...),
(c) load a bunch of teacher-defined *.sage files in examples/calculus,
(d) other stuff?
Of course, one extremely cool thing about the SAGE notebook is that you
can actually
design a special calculus control bar if you want. Maybe if you click on
help, one of the items
says calculus, and there is a link there to explain how to put a
calculus help control bar where the
normal control bar is .
All this is just brain storming. If any of it seems useful, I'm hapy to
put it on the wiki (or others
can feel free to). I'm glad this discussion is going on though!
>
> Sorry, I was sort of thinking out loud. Wrong choice of words, and not
> what I meant to say. A set of predefined indeterminates seems like a
> pretty natural thing to have, in a mathematics software suite. We
> should just make sure to explain what's really going on to people.
>
> How would this relate to the polynomial ring naming in 1.5? Will users
> confuse our predefined x, and the 'x' given for the name of a variable
> in a polynomial ring that might have been declared?
>
> I've created a wiki page for collaboration and discussion about this issue:
> http://sage.math.washington.edu:9001/BasicCalculus
>
> It doesn't have very much on it yet, but I'd like to get at the very
> least a comprehensive list of guidelines and constraints to work with.
>
> ----
> Bobby Moretti
> [EMAIL PROTECTED]
>
> >
>
>
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