[GRASS5] dgtable vector library

[Radim Blazek]

On Thursday 11 September 2003 19:15, Greg Sepesi wrote:
> Hi Radim,
> > It should stop when the destination point is reached, keep the status
> > and continue filling if new starting point is the same and destination is
> > not yet reached.
>
> That is a good idea for shortest path when it is frequently called.
> Just for my curiosity, how does GRASS use it?  

It is used in most v.net.* modules, where costs to more destination nodes are
required (v.net.iso, v.net.alloc, v.net.steiner, v.net.salesman). GRASS modules
do not store the status, they only know that to repeated call to SP from the same node
is much faster than when starting node is changed. 
Status is stored by vector library in GRASS.

> Yes I believe dglib stores results in their own tree.  Once I get a
> reentrant status, I could add the ability to optionally save it to
> disk.  This option provides a good debug/test point.  However is there a
> need to read status?  Does dglib read as well as write its result trees?

I did not mean save to disk but store in the memory, before a next call to SP
function from the same node. Sorry for confussion. Important is, that more threads
can use the same input graph at the same time.

Radim