# [Maxima] repository for contrib

sen1 at math.msu.edu sen1 at math.msu.edu
Fri Aug 4 11:37:50 CDT 2006

```First,
Thanks again for your message, for the "filer program," and for the
pointers to the commercial documentation.

I will check out the documentation you suggested, and, I am sure
that will save much time.

-sen

On Fri, 4 Aug 2006, Richard Fateman wrote:

> It sounds like you are writing a tutorial on programming in Maxima.
>
> Some of what you are describing may just be a question of re-documentation.
> Doesn't  "append"  join two lists together?
>
> There is extensive documentation, on-line, for the commercial Macsyma. It
> seems no one looks at that (not all of it relevant...) even though in some
> cases it is better than the maxima documentation.
>
> I suspect that some of the helpful programs you might provide are exercises
> in week 2 or 3 of an introductory course using Scheme or Lisp, as we have
> here in CS61a, or MIT has in course 6.001.  This is not to say that the
> programs are not useful -- just that they may emerge as natural consequences
> of thinking in a functional programming language.
>
> For example, consider filter:
>
> filter(l,pred):= if (l=[]) then [] else if pred(first(l)) then
> cons(first(l),filter(rest(l),pred)) else filter(rest(l),pred);
>
> if you define q:[a,b,c,1,2,d,e,3]
>
> then filter(q,numberp)  returns the list [1,2,3]
> and  filter(q, lambda([n],not(numberp(n))))    returns [a,b,c,d,e]
>
> This is not to say programs like filter are totally obvious, especially if
> recursion is unnatural for you...
>
> A source of ideas for (usually trivial) programs might be to look at the
> programming features of Maple or Mathematica, and see what is appealing.
> Most list-processing kinds of things can be done in a line or two of maxima.
>
> Oh, also it might be better, in some cases, to take the maxima-language
> program and rewrite it in lisp to be faster, make less intensive use of
> memory or stack, or maybe do more error checking.  Leaving the maxima
> language as documentation might be nice.
>
> I encourage you to work on this and of course get feedback from people on
> this mailing list.
>
> RJF
>
>
>
>> -----Original Message-----
>> [mailto:maxima-admin at math.utexas.edu] On Behalf Of sen1 at math.msu.edu
>> Sent: Friday, August 04, 2006 6:10 AM
>> To: maxima at math.utexas.edu
>> Subject: [Maxima] repository for contrib
>>
>> Hello,
>>   Where and how does one submit contributions of scripts and programs?
>>
>> I don't mean programs which should be included with the distribution.
>>
>> Also, for various reasons, I am trying to use "maxima" as a
>> general useful tool.  I find that there are many things
>> lacking. So, bit by bit, I am writing little useful scripts.
>>
>> For instance, just to give two examples, I have scripts to
>>
>>   join two lists together
>>   extract the sublist of zero (or nonzero) elements of a
>> numerical list
>>
>> These are easy and straightforward.  It may be that they
>>
>> It seems clear that many users are doing similar things.
>>
>> I would like to see a searchable repository of user-created
>> tools, or, if you will, a repository of "cookbook" maxima tools.
>>
>>
>> If not, perhaps the current maintainers would consider
>> setting up such a repository (as a list or accessible
>> directory, or something).
>>
>> Thanks,
>>   -sen
>>
>>
>>
>>
>>
>>
>> --
>>
>> --------------------------------------------------------------
>> -------------
>>   | Sheldon E. Newhouse            |    e-mail:
>> sen1 at math.msu.edu           |
>>   | Mathematics Department         |
>> 	   |
>>   | Michigan State University      | telephone: 517-355-9684
>>               |
>>   | E. Lansing, MI 48824-1027 USA  |       FAX: 517-432-1562
>>               |
>>
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>>
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>>
>
>

--
---------------------------------------------------------------------------
| Sheldon E. Newhouse            |    e-mail: sen1 at math.msu.edu           |
| Mathematics Department         |       				   |
| Michigan State University      | telephone: 517-355-9684                |
| E. Lansing, MI 48824-1027 USA  |       FAX: 517-432-1562                |
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