HC=1.0 is the only value that guarantee finding the optimal route by A*
algorithm, according given criteria. Higher values can provide for short
distances a/o trivial road network geometry
surprisingly wrong results.
By statistical evaluation, length of long enough routes is typically
1.2-1.3 times longer then the bee-line distance, so even for the best
roads, those values are very probably save not to miss optimal route.
Going above 1.3, the probability of missing the optimal route progressively
increases, starting to prefer those partially computed routes, that
already got closer to destination, even if they were worse. But it also
dramatically decrease computation time.
If 1.8 is used, it goes after the destination like a hunting dog.
There was not computed 1.1 either.
I guess it was chosen 1.0 as safe default,
1.2+1.3 as the grey zone
1.5 as safety challenging.
Dne 28. března 2020 13:11:24 zanny <[email protected]> napsal:
Thanks for the PDF summary, very explicative.
A couple of questions from my side (I apologise if those have been asked
and answered somewhere else already).
1) why is hc=1 the standard parameter? in 5 of 7 cases the results (in
terms of distance and travel time) is the same as hc=1.5. And in the
others, the gap between the results of hc=1 and hc=1.5 is minimal (negligible).
2) out of curiosity: is there a technical reason for factor 1.4 not being
tested?
--
You received this message because you are subscribed to the Google Groups
"OsmAnd" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/osmand/171216bf358.2799.a291d67f9894f806060d35c996ca15e9%40gmail.com.
