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<div class="moz-cite-prefix">Hi Quinton and Thomas,<br>
<br>
I'm sure there are improvements. Would be very nice to make
graphhopper aware of public transport as well.<br>
<br>
BTW: OTP is LGPL not GPL.<br>
BTW2: graphhopper is not a fork of OTP mainly because of the
hibernate and spring dependencies even in the routing package!<br>
<br>
Regards,<br>
Peter.<br>
<br>
</div>
<blockquote
cite="mid:064AA48A-378C-4D15-84E1-244D069CCA96@gmail.com"
type="cite">Hi Guys,
<div><br>
</div>
<div>Open trip planner has implemented the Raptor algorithm: <a
moz-do-not-send="true"
href="https://github.com/openplans/OpenTripPlanner/tree/master/opentripplanner-routing/src/main/java/org/opentripplanner/routing/impl/raptor">https://github.com/openplans/OpenTripPlanner/tree/master/opentripplanner-routing/src/main/java/org/opentripplanner/routing/impl/raptor</a></div>
<div><br>
</div>
<div>I can't use Open trip planner because of GPL, and it is
extremely bloated, but I did do some evaluation of the resulting
routing in London, it didn't work particularly well. But I do
get the point about the graph approach that the paper puts
forward. </div>
<div><br>
</div>
<div>So, I guess there is still room for improvement in it...</div>
<div><br>
<div>
<div>On 17 Apr 2013, at 6:08 PM, Peter K wrote:</div>
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<div class="moz-cite-prefix">Hi Quinton,<br>
<br>
thanks for pointing us to this paper (looks like <a
moz-do-not-send="true" href="http://uni-freiburg.de">uni-freiburg.de</a>
is down -> "Fast routing in very large public
transportation networks using transfer patterns")<br>
<div align="left">Also the RAPTOR paper I mentioned
earlier had some suggestions regarding efficient
storage of routes etc in the appendix <a
moz-do-not-send="true"
href="http://research.microsoft.com/apps/pubs/default.aspx?id=156567">"Round-Based
Public Transit Routing"</a><br>
</div>
<br>
Regards,<br>
Peter.<br>
<br>
<br>
</div>
<blockquote
cite="mid:485EA734-503B-453A-8767-7F319762286B@gmail.com"
type="cite">Hi Guys,
<div><br>
</div>
<div>On this topic, I assume you have seen the paper on
Transfer Patterns. It does give some nice suggestions
on the types of nodes and arcs to use for these
purpose: <a moz-do-not-send="true"
href="http://ad.informatik.uni-freiburg.de/files/transferpatterns.pdf">http://ad.informatik.uni-freiburg.de/files/transferpatterns.pdf</a></div>
<div><br>
</div>
<div>Regards,</div>
<div>Quinton Anderson</div>
<div><br>
<div>
<div>On 17 Apr 2013, at 1:38 AM, Peter K wrote:</div>
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<div class="moz-cite-prefix">Hi Thomas,<br>
<br>
regarding the size of the graph I don't expect
problems, as the world wide OSM graph
currently has over 83mio nodes.<br>
<br>
The problem is the algorithm and if it scales.
E.g. if I would use a normal bidirectional
dijkstra for a 10 000km query it would take
over 10 seconds but with a short cutting or
hierarchical algorithm like contraction
hierarchies it is under 100ms! So I'm really
excited to hear what you choose for an
algorithm :) !<br>
<br>
Regards,<br>
Peter.<br>
<br>
</div>
<blockquote
cite="mid:516D5004.9020304@student.ethz.ch"
type="cite">
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<div class="moz-cite-prefix">Thank you for
your response and offering your help.<br>
<br>
I have looked little bit into the thematic
and it seems that a implementation with a
time-expended graph would be very straight
forward. So, I would have to implement a
GTFSReader which creates the public
transport graph.<br>
Would this approach perform well with ~1
million nodes (time stops)?<br>
<br>
Regards,<br>
Thomas<br>
<br>
<br>
<br>
On 04/08/2013 09:09 PM, Peter K wrote:<br>
</div>
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cite="mid:51631606.7070708@yahoo.de"
type="cite">
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Hi Thomas,<br>
<br>
public transport would be nice to have, yes
:) <br>
<br>
But there is no time dependent datastructure
yet, and the algorithms are not tuned
regarding public transport. So, it is not
easy to implement. If you do not have much
data you can just use the GraphStorage (and
model the time via nodes), then use a-star
or dijkstra to get routes. One minor gimmick
would be the 'wayGeometry' (in EdgeIterator)
which you could use to display the real
paths between two nodes of the
trains/buses/... instead of straight line
like e.g. google does. <br>
<br>
To properly implement public transport one
would probably need to create a new Graph
interface and iterate from that, e.g. create
a simple algorithm and then use more
advanced like RAPTOR. Also a new GTFSReader
will be necessary instead of or combined
with OSMReader. <br>
<br>
If you're trying something you can be sure
to have my assistance :) ! <br>
<br>
Regards, <br>
Peter.<br>
<br>
------------------------------------------------------------<br>
<br>
Hello, <br>
<br>
I'm considering to use graphhopper for a
student project. But for that I <br>
also need support for public transport. So
I'm thinking about <br>
implementing it my own... <br>
Do you have any thoughts or plans how to
implement it and would it be a <br>
lot of work? <br>
<br>
Regards, <br>
Thomas <br>
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