[LON-CAPA-dev] Installing Modules for LON-CAPA

Guy Albertelli II lon-capa-dev@mail.lon-capa.org
Mon, 26 Sep 2005 14:21:18 -0400 (EDT)

Hi Donnell,

> I've emailed Gerd Kortemeyer a few times about maybe trying to extend
> LON-CAPA's math capabilities.  He emailed me back and said that LON-CAPA
> does in fact have the concept of a library so that new
> functions/subroutines can be added.  This is music to my ears, as I told
> him.

Gerd was referring to the .libray file in this case (as opposed to the
loading of new chunks of CPAN routines)

The .libray files are meant to be used as a place to contain common
Perl code for reuse in .problems, through the use of <import>

So to use this idea in you desires, you would in fact creat a .library
file taht contains the definitions of a variety of routines to handle
you needs (For example creat your own matrix/complex handling

I suspect the sound of that won't make you very happy.

As for this:

> module called Math::Cephes:Matrix on CPAN
> Math::Cephes:Complex on CPAN

(and additional set of routines could be Math::Complex with are part
of the standard perl install)

There is now way for instructor to 'use' an arbitrary CPAN module.

We have specifically not allowed this for a few reasons
1) each CPAN module increases the static size of each apache child,
thus increasing the amount of memory need for Lon-CAPA to run, (and as
each Apache child right now hovers in the 80-100 meg range continued
bloat here could start causing real issues.)

2) we would like for every homework problem to be able to run on any
machine in the network, and when a homework requires new softare to be
installed on the server in order to run, we would start having issues

That said, we aren't completely against adding new CPAN modules, we
just need to make sure that they are worth the costs they'll impose.

I suspect we will need to add a Complex library soon, we have had
several calls for that, (I'm leaning towards Math::Complex) and as it
looks like we are installing the Math::Cephes::Matrix routines, we
likely could add those without much issue.

guy@albertelli.com   0-7-2-1-27,137