[GraphHopper] Does Graphhopper merge ways with equal flags and name?

[John Zhao]

Hi Peter,

Could you tell me where is the merging logic?
That's interesting.

*Best Regards,*
*ZhiQiang ZHAO*

On Wed, Jun 3, 2015 at 12:09 AM, Peter <graphhopper at gmx.de> wrote:

>  Hi Jan,
>
> we do this kind of 'merging' logic already in the import step when
> deciding what should be handled as tower node and what is a pillar node.
> Otherwise you'll need as twice as many RAM when copying from one graph to
> the other.
>
>
>  > Have you made a experiment to count the number of 2 degree nodes with
> the equal flags and name in OSM?
> > And then we can know how many edges we can save.
>
> Yes, this should be done before implementing it :)
>
> And as the merging logic is currently not 100% optimal, there could be
> some minor savings even when recognizing the different street names, but
> I'm unsure if it is worth the effort.
>
> Issues like #234 or #111 will probably make more difference.
>
> Kind Regards,
> Peter
>
>
> On 02.06.2015 22:35, John Zhao wrote:
>
> Hi,
>
>  AFAIK, there is no this kind of merging logic here.
> Wait the answer from Peter.
> Probably you need to implement it by your own.
> And it's not easy.
> Maybe can be done before import?
> What you want, is actually convert a tower node to a pillar node.
>
>
>  *Best Regards,*
> *ZhiQiang ZHAO*
>
> On Tue, Jun 2, 2015 at 1:27 PM, Jan Torben Heuer <jan at komoot.de> wrote:
>
>> Hi ZhiQiang ZHAO,
>>
>>  Thanks for your quick answer.
>> I have a custom FlagEncoder that imports only very few ways and I don’t
>> need the names. I guess, I have mostly nodes with a degree of two.
>>
>>  Jan
>>
>>  Am 02.06.2015 um 21:53 schrieb John Zhao <johnthu at gmail.com>:
>>
>>  Hi,
>>
>>  Have you made a experiment to count the number of 2 degree nodes with
>> the equal flags and name in OSM?
>> And then we can know how many edges we can save.
>>
>>  I doubt this should be not too much for OSM.
>>
>>  *Best Regards,*
>> *ZhiQiang ZHAO*
>>
>> On Tue, Jun 2, 2015 at 11:59 AM, Jan Torben Heuer <jan at komoot.de> wrote:
>>
>>> Hi,
>>>
>>> Can Graphhopper merge two ways with equal flags and name if there is no
>>> intersection between them (no third way connected)?
>>>
>>> I would like to create a very reduces graph with only few edges. What
>>> would be the easiest way to achieve it? I think I would have to disable the
>>> nameIndex for instance.
>>>
>>> Thanks,
>>>
>>> Jan
>>>
>>>
>
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