[pgrouting-users] dijkstra for MANY sources

[Stephen Woodbridge]

On 11/14/2016 2:12 AM, Brian DeRocher wrote:
> Hey there,
>
> Can someone give me some guidance.  I'm looking for the right
> algorithm to use when solving this problem.  I want to find the
> distance and shortest path to 11 schools for about 15,000 students.
> Does the many to many flavor of dijkstra scale up to these numbers?
> Is there a better way to solve this?

Hi Brian,

Checkout

http://docs.pgrouting.org/2.2/en/src/dijkstra/doc/pgr_dijkstraCost.html

It has a many to one function.

Regarding performance, that depends on a lot of issues but I would think 
if your limiting your edge table to the roads in the school district 
that you should get reason able performance.

You might want to try running it with 10, 100, 1,000, 15,000 so you have 
some idea of the performance at various numbers of nodes.

you will need to map the locations to the node ids in the network, then 
pass the node ids to the function.

Ask if you need more explicit help.

-Steve W

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus