Re: Octave projects

[David Bateman]

Ivana Varekova wrote:

> > Want to implement the sparse graph theory stuff. That is etreeplot, 
> > treeplot, gplot and treelayout. I couldn't be bothered with these 
> > functions when implementing the sparse stuff, so if someone else doesn't 
> > implement them, they won't be implemented :-)
> >    
>
> Hello,
> I think sparse graph theory is quite nice topic and it should be fine
> work, so if there is not any problem I would choose it. Are there any
> information, advices or suggestions I should know before I start to
> implement these procedures?   
> (I can't find any other part of the graph theory in octave. Is there any
> other graph theory stuff?)
> Thanks.
> Ivana
The only things implemented are etree and symbfact and symbfact was only 
committed to the CVS this week, so is very much bleeding edge. You 
should probably therefore be using the CVS version of octave to do this.

My typical way of attacking such a problem is to read the documentation 
of the competition very carefully at

http://www.mathworks.com/access/helpdesk/help/techdoc/math/sparse.html

and in this case in particular the function summaries and adjacency 
graph stuff. I don't read the matlab source code and I also don't read 
the documentation when writing the equivalent documentation for octave 
due to issues of contamination of the octave with non GPL code. However, 
it is useful to have matlab available if possible to test the code and 
things that aren't well explained in their documentation.

Not knowing much about graph theory myself (hey I'm an engineer not a 
mathematician), I'd say that implicitly graph theory is another way of 
considering the structure of sparse matrices as adjacency graphs, and so 
implicitly there is a strong link between the two. Therefore, I don't 
expect there is any graph theory stuff for octave. You might be able to 
find some stuff at

http://www.mathworks.com/matlabcentral/fileexchange/loadCategory.do

that might be freely used, and is probably mostly compatible with 
octave.. Note if it is it be included in octave it will need to be 
conformant with the octave coding style. So even if the code you find 
runs it will need to be converted. See examples of other scripts in 
octave and how they are written, including particularly the texinfo help 
string.

Regards
David

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David Bateman                                address@hidden
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