[GRASSLIST:6648] v.net.path cost function?

[Ryan D Taylor]

Hi,

I'm just wondering what the v.net.path module uses to determine the 
default cost of an arc.  It doesn't seem to be distance as this is the 
shortest path it gave me between 2 nodes:

http://www.cs.utah.edu/~ryant/shortestpath.gif

Also, as some background information, this is what i've done to generate 
the shortest path.  I started with some vector data called "slc" which 
contains real road data, then I ran a v.net to generate a vector map 
called "nodesmap" with the node data. then i did a v.category with  
"nodesmap" as the input and "categorymap" as 
the output.  Finally I did a v.net.path with "categorymap" as input and 
"shortestpath" as the output--which you can see in red in the gif file. 

Ultimately I'm trying to determine a shortest path between two points that 
takes into account more than distance.  My original vector data set 
contains columns that describe speed limits, road directions, road 
quality, etc.  How could I get v.net.path to take several fields like that 
into account?  Also, since I'm generating the "shortestpath" vector map 
from "categorymap" and not from my original dataset "slc", how can I 
specify to v.net.path to take into account values from "slc"?

Thanks for any help you can give me.  I really appreciate it.

Ryan T.