[cl-graph-devel] Graph failed to render

[Gary King]

Hi Joel,

How are you generating the DOT file? If you use the dot-attributes  
stuff (found in graphviz-support.lisp), then the output is OK for  
integer weights and an error is generated for non-integer weights.

> ;; gotta fix this mixin disease
> (defclass foolish-directed-edge
>           (dot-edge-mixin
>            directed-edge-mixin
>            weighted-edge-mixin
>            graph-container-edge)
>   ())
>
> (let ((g (make-container 'dot-graph
>                          :directed-edge-class 'foolish-directed-edge
>                          :default-edge-type :directed)))
>   (add-edge-between-vertexes g :a :b :weight 10 :dot-attributes  
> '(:weight 10))
>   (graph->dot g t))
>
> digraph G {
> graph [];

1 [];
0 [];
0->1 [weight=10];
}
#<DOT-GRAPH 2 #x7584BD6>
?

On the other hand, this is kludgy because the weight of the edge must  
be specified twice (once for the slot, once for the dot-attribute  
(ugh!).

Since GraphViz's restriction on weights is artificial, I think that  
the right way of handling this is to expose enough machinery so that  
the person creating the DOT file can specify how to translate a  
weight into an integer and to arrange things so that the dot- 
attribute classes use the edge weight from weighted-edge (if it is  
there) instead of overriding it.

Does that make sense?


On Mar 6, 2006, at 12:23 PM, Joel Reymont wrote:

> Thank you Gary! Please let me know when I can download the patches.
>
> On Mar 6, 2006, at 5:04 PM, Gary King wrote:
>
>> Hi Joel,
>>
>> There first problem was that GraphViz didn't like the Lisp double  
>> float notation (e.g., 1.0d0). Removing all of those leads to the  
>> second problem: GraphViz wants all of the weights to be integers.
>
> --
> http://wagerlabs.com/
>
>
>
>
>


-- 
Gary Warren King
metabang.com
http://www.metabang.com/