[GraphHopper] Data graph

[Peter]

Hi Alexander,

GraphHopper is an open source project where everything happens on your
machine and a country-sized graph should fit into 1-2GB RAM. The
GraphHopper Directions API is a durable, hosted GraphHopper (and other
features) with multiple profiles for world wide coverage etc

Regards,
Peter

On 24.06.2015 12:01, Alexander Tkachov wrote:
> And what is the size of such graph?
> I mean, if there opportunity to download some peace of the graph? It
> will improve processing time (because the graph will be in memory) and
> reduce your server workload.
>
> Thanks a lot for the information.
>
> On Wed, Jun 24, 2015 at 11:44 AM, Peter <graphhopper at gmx.de
> <mailto:graphhopper at gmx.de>> wrote:
>
>     Hi Alexander,
>
>     first, you should get yourself familiar on e.g. how a simple route
>     <https://github.com/graphhopper/graphhopper/blob/master/docs/core/routing.md>
>     can be calculated with the default algorithms from GraphHopper.
>
>     Then for your new algorithm you can use the low level API
>     <https://github.com/graphhopper/graphhopper/blob/master/docs/core/low-level-api.md>
>     where you have direct access to the Graph object:
>     Graph graph = graphHopper.getGraph();
>
>     Read a bit about tower vs. pillar nodes, and try to traverse the
>     graph its 'junctions' and implement the algorithm for it. As an
>     example you can have a look into Dijkstra.java
>     <https://github.com/graphhopper/graphhopper/blob/master/core/src/main/java/com/graphhopper/routing/Dijkstra.java>.
>
>     Also read about custom weighting
>     <https://github.com/graphhopper/graphhopper/blob/master/docs/core/weighting.md>
>     and flag encoders
>     <https://github.com/graphhopper/graphhopper/blob/master/docs/core/create-new-flagencoder.md>.
>
>     Kind Regards,
>     Peter
>
>
>     On 24.06.2015 11:31, Alexander Tkachov wrote:
>>     Hi.
>>     I have a problem. I want to implement my own search algorithm
>>     (the shortest path between two points on map for cars). For these
>>     purposes I need some kind of graph (or something else). If there
>>     opportunity to get crossroads graph? I mean, I need something,
>>     which contains crossroads where each crossroads contains
>>     coordinates, the list of nearest crossroads and distances (m or
>>     km) to these nearest crossroads. If there will be any other
>>     parameters (like speed limits etc) it will be great.
>>     How can I get such kind of data if on the beginning I have only
>>     coordinates of start and end points.
>>
>>     Thanks.
>>

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