On Thursday, March 5, 2020 at 5:44:36 PM UTC+1, Harry van der Wolf wrote:
>
>
> The issue is OsmAnd and its heuristic coefficient of 1.0. Not any other 
> application is doing that.
>
>
Hi Harry,

it's not that easy. BRouter is operating at heuristic coefficient = 1.0. 
Going heuristic is "unconditional surrender" and leads to artefacts that 
can be easily detected.

I think what mapactor, waze and the like are doing are "hierachical 
constraints",which is about as bad, but not so easy to detect.

For BRouter I worked on 2 aspects:

- the raw "node crunching power", which is about 1 Million nodes/seconds on 
a server-processor-core, or 100k/second on a smartphone. This is just 
engeneering and tuning. You cannot compare the osmand-router with BRouter 
here: BRouter is working on specilized data files which are 8% in size of 
usual OSM data and contain the street network only, while OSMAND data are 
170% of usual OSM data size. 

- the other aspect is the "averge cost factor", so the ratio of average 
versus minimal cost, which should be close to 1 and is e.g. about 1.05 for 
the "car eco" profile, 1.16 for "car fast". It's important to be close to 1 
here to keep the search area small.

regards, Arndt

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