[GraphHopper] Graphhopper using dijkstra's algo directly with graph

[Peter K]

Hi Quinton,

you will be able to import POIs into graphhopper. Then you'll be able to
do something like
List<Path> resultingPaths = graphhopper.route(fromLocation, "restaurant");
to get a list of paths sorted by distance or time.

For the faster algorithm however (currently contraction hierarchies) one
needs to specify the location of the POIs explicitly.

Regards,
Peter.

> Hi Peter,
>
> Search for the points and route via those points? 
>
> Thanks. 
> On 09 May 2013, at 8:49 PM, Peter K wrote:
>
>> [forwarded to mailing list]
>>
>> Hi Zongjie,
>>
>> have a look into the low level API:
>> https://github.com/graphhopper/graphhopper/wiki/Low-Level-API
>>
>> and the relative efficient one-to-many dijkstra:
>> https://github.com/graphhopper/graphhopper/blob/master/core/src/main/java/com/graphhopper/routing/DijkstraOneToMany.java
>> where the distance limit is already implemented ('limit')
>>
>> In the near future one will be able to search for points of interests in
>> a certain radius, which will be probably similar to what you want.
>>
>> Regards,
>> Peter.
>>
>>> Hi Peter,
>>>
>>> I have been using your graphhopper api for my final year project and
>>> it has been great! However, I need to make some changes to my project
>>> which I would like to request for your help.
>>>
>>> I know that graphhopper is providing routing capabilities through
>>> reading of the graph of a map and using the various algorithms to
>>> return an array of geopoints of the calculated path.
>>>
>>> What I would need your help on is may I know if i can directly access
>>> the graph and apply the dijkstra's algorithm on it? Because what I
>>> actually need is geopoints that are of a certain distance away from
>>> the current location.
>>>
>>> For example: I am at point A, and I request for the road distance of
>>> 5KM away from point A.
>>>
>>> I was thinking that by using the dijkstra's algo I would be able to
>>> traverse through the nodes of the graph till I find all the 5KM nodes
>>> that are away from the current location's node.
>>>
>>> Currently I am using your graphhopper API to get the distance and
>>> geopoints that are of fixed angles from the current location. Let's
>>> say 0 degrees, 90 degrees, 180 degrees and 270 degrees. So I will get
>>> 4 routes using your API which I will then access the individual route
>>> to find the 5KM geopoints I required to get my 5KM points away from
>>> the current location.
>>>
>>> Is there any way I can use your dijkstra's algo and access the graph
>>> directly which then can provide me with the distance and geopoints of
>>> each node it traversed using the algo. I believe with this, I would be
>>> able to get all the geopoints that are of certain distance away from
>>> the current location more effectively and efficiently!
>>>
>>> Thank you for taking your time to read this and I hope to receive your
>>> kind response soon!
>>>
>>> Best Regards,
>>> Zongjie Ng