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<div class="moz-cite-prefix">Hi Alexander,<br>
<br>
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<br>
<br>
Regards,<br>
Peter<br>
<br>
On 24.06.2015 12:01, Alexander Tkachov wrote:<br>
</div>
<blockquote
cite="mid:CAGGswp_h0qLUc=jLuJv1JB_NBSArHqq_xYDteYu+Nn_SW8oJvw@mail.gmail.com"
type="cite">
<div dir="ltr">And what is the size of such graph?
<div>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.</div>
<div><br>
</div>
<div>Thanks a lot for the information.</div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Wed, Jun 24, 2015 at 11:44 AM, Peter
<span dir="ltr"><<a moz-do-not-send="true"
href="mailto:graphhopper@gmx.de" target="_blank">graphhopper@gmx.de</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Hi Alexander,<br>
<br>
first, you should get yourself familiar on e.g. how a <a
moz-do-not-send="true"
href="https://github.com/graphhopper/graphhopper/blob/master/docs/core/routing.md"
target="_blank">simple route</a> can be calculated
with the default algorithms from GraphHopper.<br>
<br>
Then for your new algorithm you can use the <a
moz-do-not-send="true"
href="https://github.com/graphhopper/graphhopper/blob/master/docs/core/low-level-api.md"
target="_blank">low level API</a> where you have
direct access to the Graph object:<br>
Graph graph = graphHopper.getGraph();<br>
<br>
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
<a moz-do-not-send="true"
href="https://github.com/graphhopper/graphhopper/blob/master/core/src/main/java/com/graphhopper/routing/Dijkstra.java"
target="_blank">Dijkstra.java</a>.<br>
<br>
Also read about custom <a moz-do-not-send="true"
href="https://github.com/graphhopper/graphhopper/blob/master/docs/core/weighting.md"
target="_blank">weighting</a> and <a
moz-do-not-send="true"
href="https://github.com/graphhopper/graphhopper/blob/master/docs/core/create-new-flagencoder.md"
target="_blank">flag encoders</a>.<br>
<br>
Kind Regards,<br>
Peter
<div>
<div class="h5"><br>
<br>
On 24.06.2015 11:31, Alexander Tkachov wrote:<br>
</div>
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<div>
<div class="h5">
<div dir="ltr">Hi.
<div>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.</div>
<div>How can I get such kind of data if on the
beginning I have only coordinates of start and
end points.</div>
<div><br>
</div>
<div>Thanks.</div>
</div>
<br>
</div>
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