Never mind what I said in the message below.
I just thought about it for another 30 seconds and
the stuff I wrote was mostly off the mark.
best,
Robert Dodier
On 6/18/11, Robert Dodier <robert.dodier at gmail.com> wrote:
> On 6/17/11, carolus <worwor at bellsouth.net> wrote:
>> On 6/17/2011 11:15 AM, Robert Dodier wrote:
>
>>> (Yes, it is unclear and confusing to try to distinguish
>>> between programming functions and symbolic functions.
>>> Sorry about that.)
>
>> What is the difference? I've noticed "f(x) :=" for function definition
>> and "f[x] :=" for initializing matrices. Is that what you are talking
>> about?
>
> Well, in conventional programming languages, the argument
> of a function must evaluate to some appropriate type,
> otherwise the function barfs out an error.
> Maxima and other symbolic math systems can handle
> inappropriate arguments via partial evaluation.
> e.g. when x and y are numbers, then x + y => number.
> But if x, say, x is a symbol and y is a number, then x + y => x + number.
> Later on, when x has a numeric value, you can reevaluate it
> and get x + number => number.
>
> Anyway, Maxima has some functions which act like ordinary
> programming language functions, and "first" is one of them.
> The argument of first must be a list, otherwise it's an error.
> On the other hand, subscripts like x[1] are OK when x is
> not any subscriptable object.
>
> best
>
> Robert Dodier
>