[LON-CAPA-users] loading a maxima package for use

[Peter Riegler]

Hi Jay,

mean requires load (descriptive). "load" is blacklisted.
Blacklisted are
'save','load','plot','lisp','includ','compil','file','batch','stringout','translat','stout','stin','block','system','concat','read','inchar',
'outchar','ttyoff','with_stdout','writefile','reset'
which are considered to be potentially harmful (allowing file system or 
OS access).
I had a discussion with Gerd&Guy about it. We basically agreed on having 
  an extra attribute allowing to load trusted maxima packages. 
Unfortunately none of us seems to have time to realize this.

Maybe defining your own function is a suitable workaround:
(%i1) mymean(x):=apply("+",x)/length(x);
                                        apply("+", x)
(%o1)                     mymean(x) := -------------
                                          length(x)
(%i2) mymean([1,2,3,4]);
                                        5
(%o2)                                  -
                                        2


Peter


Jay Sullivan wrote:

> Let's say I want to use the "mean" function inside the 'descriptive' 
> package of maxima.
> 
> How can I access that through loncapa. I got a "blacklisted error" when 
> I tried to put it all in one command line.
> 
> Thanks,
> Jay
> 

-- 
Peter Riegler
Fachhochschule Braunschweig/Wolfenbüttel
Salzdahlumer Str. 46/48, 38302 Wolfenbüttel
Tel. +49 5331 939 6314, Fax. +49 5331 939 6002
email: p.riegler@fh-wolfenbuettel.de
http://public.rz.fh-wolfenbuettel.de/~riegler