[GRASS-user] Compiling addons from svn repository

[Moritz Lennert]

On 04/08/08 13:39, gianluca massei wrote:
> Hy list,
> I'm writing a C module for multiciriteria decision analysis in GRASS. 

Great news ! I'm very interested in this.

If you haven't already, you might want to have a look at the old r.infer 
and r.weight modules in grass5.4. Also see the GRASS news article by 
Peter Löwe: http://grass.itc.it/newsletter/grassnews3.html.

Just one suggestion: it might be worthwhile thinking about error 
handling/propagation in such a module...

> I've a problem with doublevalue  multiple answers processing.
> The code is like that:
> "
> /    weight = G_define_option();
>  weight->key        = "weight";
>  weight->type       = TYPE_DOUBLE;
>  weight->required   = YES;
>  weight->multiple   = YES;      weight->description = _("Criteria 
> weight(s) (w1,w2,..)");/
> "
> 
> I'd like extract single value so, I tried this:
> "
> /    for(i=0;i<ncriteria;i++)
>      {
>      G_message(_("Peso %d : %lf"),i,weight->answers[i]);
>      }/
> "

Not sure, but I think the ->answers are always string, so you have to 
transform to float with atof:

G_message(_("Peso %d : %lf"),i,atof(weight->answers[i]));

Moritz