[GraphHopper] adding adaptivity to graphhopper

[Peter]

Hey Vivek,

first, you'll have to disable CH which is enabled by default to provide
this kind of flexibility I think.

And instead of putting the logic in the encoder I would probably use a
customized Weighting which does the things you mentioned:
1. reads the user demand or
2. can read a particular information from an edge (like polluted,
noisy,...).

For this more generic encoding I introduced methods like
FlagEncoder.set/getLong/getBool/getDouble a few days ago.


> Would different users demanding different characteristics screw up any
caching that GraphHopper does?

Not sure if you refer to CH when you say 'caching'. But yes different
user demands are not really possible with CH.

Regards,
Peter.


> Hi
>
> I'm a researcher working at Trinity College Dublin, and I'm looking at
> the possibility of adding adaptivity to GraphHopper. To elucidate, I'm
> looking at multiple kinds of needs of users:
>
> a) The user desires a route with particular characteristics (least
> polluted, least noisy, etc.)
> b) When multiple users all demand a particular route, during a given
> timeframe (say for a music concert), the algorithms try to provide
> slightly different routes to each user, so as to minimize the chance
> of a traffic jam.
>
> For Task (a), I think the key is to add multiple encoders (in the
> routing/util/ directory) all descended from AbstractFlagEncoder, and
> have them responsible for adding different weights to different
> routes/roads. Is this correct? Would different users demanding
> different characteristics screw up any caching that GraphHopper does?
>
> Just wanted to ask the opinion of the list, if they had any
> ideas/suggestions/stuff-already-tried, etc. Obviously, all successful
> implementations will be added back to the graphhopper community.
>
> regs
> Vivek
>
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