<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"></head><body ><div><div></div><div><br>Hi,<br><br>What is the current support for matrix calculations (i.e. n source points to n target points) using contraction hierarchies in the open source graphhopper code?<br><br>I found this post from last year<br><br>https://lists.openstreetmap.org/pipermail/graphhopper/2013-July/000254.html<br><br>I think I understand the principle behind caching each shortest path tree from your n source points - it's similar to what they do in the paper 'Computing Many-to-Many Shortest Paths Using Highway Hierarchies' by Knopp et al.<br><br>This way you should be able to just run 2 x n shortest path tree calculations with contraction hierarchies - one for each direction as CH is bi-directional, yes?<br><br>As the caching, combining of results etc is probably quite complex, is this currently implemented in graphhopper or will it be in the near future?<br><br>Many thanks,<br><br>Phil</div><div><br></div><div><br></div><div><div style="font-size:75%;color:#575757">Sent from Samsung Mobile</div></div></div> <br><br><br>-------- Original message --------<br>From: Emux <devemux86@gmail.com> <br>Date: <br>To: GraphHopper Java routing engine <graphhopper@openstreetmap.org> <br>Subject: Re: [GraphHopper] Cruiser (mapsforge) and GraphHopper <br> <br><br>
<div class="moz-cite-prefix"><b>
<div class="moz-cite-prefix"><a href="https://play.google.com/store/apps/details?id=gr.talent.cruiser"><b>Cruiser
1.2.4</b></a><br>
<a href="https://play.google.com/store/apps/details?id=gr.talent.cruiser.beta"><b>Cruiser
Beta 1.3.12</b></a><br>
<br>
Now both have <b>offline routing</b> via GraphHopper.<br>
<br>
<br>
On 27/4/2014 21:08, emux wrote:<br>
</div>
<blockquote cite="mid:535D47BB.5050302@gmail.com" type="cite">
<meta http-equiv="content-type" content="text/html;
charset=ISO-8859-7">
Cruiser is an Android map and navigation application using offline
vector maps (Mapsforge).<br>
<br>
<a moz-do-not-send="true" href="https://play.google.com/store/apps/details?id=gr.talent.cruiser.beta"><b>Cruiser
Beta 1.3.9</b></a> (mapsforge <b>rescue-exp 0.5.0</b> &
render theme <b>v4</b>)<br>
<br>
<b>- Offline routing (GraphHopper)</b><br>
<br>
The graph folder can be defined at 'Settings' - 'Navigation'.<br>
Cruiser supports graphs with contraction hierarchies enabled or
disabled.<br>
<br>
<i>From Wiki:</i><i><br>
</i><i><a moz-do-not-send="true" href="https://github.com/graphhopper/graphhopper/blob/master/docs/core/ch.md">Contraction
hierarchies</a> is a post-import process which makes routing
faster (bidirectional algorithms).</i><i><br>
</i><i>At the moment only one travel mode (usually car) can be
used if contraction hierarchies is enabled.</i><i><br>
</i><i>A more flexible routing (but slower) with multiple travel
modes (car, bike, foot) requires graphs with contraction
hierarchies disabled.</i><i><br>
</i><br>
I have created contraction hierarchical graphs for some regions.<br>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://www.talent.gr/public/graphs/">http://www.talent.gr/public/graphs/</a><br>
There are also some no contraction hierarchical graphs, having the
suffix '_vehicles'.<br>
<br>
<i>You can email me if you need more graphs.</i><br>
</blockquote>
<br>
<div class="moz-signature">-- <br>
<font color="#000000">Emux</font><br>
<a href="http://wiki.openstreetmap.org/wiki/Cruiser">Cruiser</a> -
<a href="http://wiki.openstreetmap.org/wiki/Atlas_%28navigation_application%29">Atlas</a></div></b></div>
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