[pgrouting-dev] GSoC 2019

[Stephen Woodbridge]

Hi Guanzhong,

I think your need to find the current pgrouting workshop (a tutorial) 
and work your way through it. What you describe is already possible 
because of the integration with postGIS and postgresql. For example you 
can select your edges for building a graph like:

-- in pseudo-sql
select * from edge_table
  where geom && st_expand(start, radius)
         or geom && st_expand(end, radius)
         or geom && st_make_line(start, end);

But this has nothing to do with driving directions. Driving directions 
assumes you already have the shortest path and you neeed to turn that 
into maneuvers and then into natural language.

-Steve

On 2/18/2019 1:52 AM, 刘冠中 wrote:
> Hello Steve,
>
> Very happy to receive your letter.
>
> This is some of my ideas.
>
> We need a search range to find a path planning solution.I have three 
> ideas：
>
> 1.Build a rectangle from the start point to the end point.
> 2.Build an ellipse from the start point to the end point
> 3.Combine the two to find their common area
> /*Concept map in the attachment*/
>
> And I have two questions：
>
> 1.Is there a grade distinction between roads, and whether 
> stratification can improve efficiency?
> 2.The limits of each road should also be considered. Can we get 
> relevant information?
>
>
>
> Guanzhong Liu
> 在 2019年2月16日 +0800 PM10:51，Stephen Woodbridge 
> <stephenwoodbridge37 at gmail.com>，写道：
>> Hello Guanzhong,
>>
>> Here is an outline for Driving Directions that I wrote up a few years 
>> ago.
>>
>> https://github.com/pgRouting/pgrouting/wiki/Driving-Direction-Instructions
>>
>> It discusses an approach to the problem and identifies some of the issue
>> that need to be overcome or worked around. One thing you might want to
>> do is to take a small data set like your city and get that working in
>> pgrouting, then following the outline above try to get some of the steps
>> working with that data. You can prototype this up in plpgsql stored
>> procedures. My original implementation was done in plpgsql which was
>> very fast and adequate for the task.
>>
>> I would break this down into two major task:
>> 1. the algorithms for generating the maneuvers and explicating the
>> directions
>> 2. working out the details of how to make the solution generic
>>
>> Step 1. sets many of the requirements for step 2, like what is the
>> minimum data needed for the analysis because this then needs to be
>> configured in the generic solution, etc.
>>
>> I think this would be a very valuable contribution to pgrouting.
>>
>> Best regards,
>>   -Steve
>>
>> On 2/16/2019 6:32 AM, 刘冠中 wrote:
>>>
>>> Hello，
>>>
>>>
>>> I am a senior at Beijing Institute of Technology in China. My major at
>>> university is computer science and technology. And Coding also is my
>>> hobby. Path planning is a topic I attended in the lab. I am very
>>> interested in your thoughts on "Implement generic driving directions
>>> add-on to pgRouting”.
>>>
>>>
>>> Thank you for reading and look forward to your reply.
>>>
>>>
>>> Guanzhong Liu
>>>
>>>
>>> _______________________________________________
>>> pgrouting-dev mailing list
>>> pgrouting-dev at lists.osgeo.org
>>> https://lists.osgeo.org/mailman/listinfo/pgrouting-dev
>>
>>
>>
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