[GraphHopper] Closest edge lookup

[Peter]

Hi Laurent

> it says that one should try to « decrease prepare.minNetworkSize », is
that correct or do you mean actually « increase » the value ? and

No :)
as you already figured out. minNetworkSize specifies the number of nodes
to recognize it as a standalone island. If you increase the default
value bigger islands will be removed.

> Well done !

Well ... it is a simple solution for one-vehicle-graphs. There are more
complex solution still on our todo list

> Any drawback to raising this value to large numbers ?

yes, real islands should not be removed :)

Peter


On 01.03.2015 10:27, Laurent Bendel wrote:
> OK, I’m a happy camper. prepare.minOnewayNetworkSize=800 seems to do
> the trick. One needs to rebuild the graph though; by looking at the
> code, it looks like it discards these non-reachable islands at graph
> building time, which is exactly what I need. Well done ! Any drawback
> to raising this value to large numbers ?
>
> Laurent
>
> On 1 mars 2015, at 09:47, Laurent Bendel <asianrider at gmail.com
> <mailto:asianrider at gmail.com>> wrote:
>
>> Peter,
>> yes, I think you’ve put the finger on the problem: my map has lots of
>> small ways that are not connected to the rest of the graph. So I
>> think it actually finds an edge to start off with, but then it can’t
>> find a route because it’s an island, although not a « oneway
>> island », just an isolated island. So is the config
>> prepare.minOnewayNetworkSize although useful in this case ?
>>
>> In the SO issue you mention, it says that one should try to
>> « decrease prepare.minNetworkSize », is that correct or do you mean
>> actually « increase » the value ? and then should I recompile and
>> rebuild the graph when I play with this value or can I just restart
>> the server ?
>>
>> Thanks,
>> Laurent
>>
>> On 28 févr. 2015, at 21:16, Peter <graphhopper at gmx.de
>> <mailto:graphhopper at gmx.de>> wrote:
>>
>>> The default settings should be already sufficient for ~1000m
>>> Maybe your start point is in a trap due to a barrier or similar?
>>> Maybe you try http://stackoverflow.com/a/26433076/194609
>>>
>>> Kind Regards,
>>> Peter
>>>
>>>
>>> On 28.02.2015 17:27, Laurent Bendel wrote:
>>>> Hi all,
>>>> no answer, but I’ve found these two setting in config.properties,
>>>> which I changed as follows:
>>>>
>>>> index.highResolution=1000
>>>> index.maxRegionSearch=8
>>>>
>>>> But it doesn’t seem to help. First question is, do I need to
>>>> recompile after changing these two variables ? do I need to rebuild
>>>> the graph ? well, I did both anyway, but it still sometimes returns
>>>> « point 0 not found » when the coordinates is more than around
>>>> 300-500m from the nearest road. Do I need to change something else ?
>>>>
>>>> Thanks,
>>>> Laurent
>>>>
>>>>
>>>> On 23 févr. 2015, at 19:08, Laurent Bendel <asianrider at gmail.com
>>>> <mailto:asianrider at gmail.com>> wrote:
>>>>
>>>>> Hi all,
>>>>> I’m trying to find which option controls the max distance taken in
>>>>> account when looking up the closest edge for the start and end
>>>>> point given in a search. In some areas that are very poorly
>>>>> mapped, it’s sometimes possible to give a coordinate that is too
>>>>> far away from the closest road and the server returns an error.
>>>>> I’d like to increase this value.
>>>>>
>>>>> Thanks,
>>>>> Laurent
>>>>>
>>>>
>>>

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