[pgrouting-dev] Greetings!!

Rohith Reddy rohithreddy2219 at gmail.com
Thu Feb 15 22:59:59 PST 2018


Hello Sourabh,

Sorry for the delayed response. According to my understanding the doc
explains the practicality of shortest path problem. It also defines two
metrics that can be used for  computing shortest yet fastest path.

   1. *Road Segments*
   This metric can be used in pgRouting, provided you have the data about
   betweenness and length of edges. If you had a chance to look at the
   documentation of pgRouting, here
   <http://docs.pgrouting.org/2.5/en/pgr_dijkstra.html#description-of-the-edges-sql-query-for-dijkstra-like-functions>
you
   can find that the *cost *column represents the weight of the road. The
   *cost* column can represent length of the road, travel time on the road
   or any such metric which is to be minimised while computing
shortest path. In
   this case the metric you provided can be used as the *cost* column for
   path computation in pgRouting.

   2. *Junctions (intersections)*
   This functionality had a complete rewrite last year as a part of GSoC
   2017. Firstly the given graph was modelled as line graph
   <https://en.wikipedia.org/wiki/Line_graph> that captures the turn costs,
   and this line graph was further used for computing shortest path. The
   metric you provided in this case can be used as a *cost* in the *line
   graph*. You can find further details about the project here
   <https://github.com/pgRouting/pgrouting/wiki/GSoC-2017-Rewrite-TRSP>.

    It would be interesting to try and analyse the difference between the
   shortest path(based on length) and shortest path(based on the above
   metrics) on real world road network data like Open Street Maps.

Regards,
Rohith Reddy.

On Fri, Feb 16, 2018 at 12:43 AM, Sourabh Garg <
sourabh.gargcd.mat14 at iitbhu.ac.in> wrote:

> Hello Everyone,
>     In reference to my earlier mail, I look forward to hearing some
> feedback or guidance on my proposed idea. So, that I start working with the
> organization as early as possible. I have started researching some ideas:
> multi-modal path problem, truck and trailer routing and generic driving
> direction. I would be glad if I can get help regarding them.
> Thanks,
>
> -Sourabh Garg
>
> On Thu, Feb 8, 2018 at 2:23 AM, Sourabh Garg <sourabh.gargcd.mat14 at iitbhu.
> ac.in> wrote:
>
>> Hello Everyone,
>>           I am a fourth year integrated dual degree(BTech+MTech)
>> student from IIT(BHU) pursuing Mathematics and Computing. I am quite
>> interested in working with the pgRouting organization(OSGeo).
>>
>> Earlier I had been doing my Btech project on graph theory titled "Graph
>> theoretical modeling of Institution campus". Under one subtopic of this
>> project, I worked on "Fastest-cum-shortest route between two nodes" which
>> involves relative travel time at road segments as well as turns(junctions).
>> I find it as a more generalized version of one of last year's GSoC project
>> "Turn Restricted Shortest path algorithm". I have attached the link to
>> this, please review and your guidance would be very helpful for me.
>> I have also been intrigued by Gsoc ideas for this year like
>> multi-modal transportation, generic driving instruction, trailer problem,
>> these are quite relatable to my work.
>> I look forward to hearing from you.
>> Thank you
>>
>> Link: https://docs.google.com/document/d/14NkVVZPXPruYrS1_Aw
>> 5i0z_Ltpoojj2EJqMqmfW3oG4/edit?usp=sharing
>>
>> Sincerely,
>> *Sourabh Garg*
>> Senior Undergraduate
>> Mathematics and Computing
>> Indian Institute of Technology(BHU) Varanasi <http://iitbhu.ac.in/>
>> LinkedIn: Sourabh Garg
>> <https://www.linkedin.com/in/sourabh-garg-14658a110/>
>> Mobile: +91-8764021751
>>
>>
>>
>>>>
>
>
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