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Parameter tuning for different route lengths

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Patrick Niklaus 2018-04-22 16:34:31 +00:00 committed by Patrick Niklaus
parent 61101db8cf
commit 77a740c0fb
1 changed files with 12 additions and 9 deletions
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21
src/engine/routing_algorithms/alternative_path_mld.cpp
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@ -47,13 +47,13 @@ struct Parameters
double kAtMostLongerBy = 0.25; double kAtMostLongerBy = 0.25;
// Alternative paths similarity requirement (sharing). // Alternative paths similarity requirement (sharing).
// At least 15% different than the shortest path. // At least 15% different than the shortest path.
double kAtLeastDifferentBy = 0.85; double kAtMostSameBy = 0.85;
// Alternative paths are still reasonable around the via node candidate (local optimality). // Alternative paths are still reasonable around the via node candidate (local optimality).
// At least optimal around 10% sub-paths around the via node candidate. // At least optimal around 10% sub-paths around the via node candidate.
double kAtLeastOptimalAroundViaBy = 0.1; double kAtLeastOptimalAroundViaBy = 0.1;
// Alternative paths similarity requirement (sharing) based on calles. // Alternative paths similarity requirement (sharing) based on calles.
// At least 15% different than the shortest path. // At least 15% different than the shortest path.
double kCellsAtLeastDifferentBy = 0.85; double kCellsAtMostSameBy = 0.85;
}; };
// Represents a via middle node where forward (from s) and backward (from t) // Represents a via middle node where forward (from s) and backward (from t)
@ -140,27 +140,30 @@ Parameters parametersFromRequest(const PhantomNodes &phantom_node_pair)
if (distance < 10000.) if (distance < 10000.)
{ {
parameters.kAlternativesToUnpackFactor = 10.0; parameters.kAlternativesToUnpackFactor = 10.0;
parameters.kCellsAtLeastDifferentBy = 1.0; parameters.kCellsAtMostSameBy = 1.0;
parameters.kAtLeastOptimalAroundViaBy = 0.2; parameters.kAtLeastOptimalAroundViaBy = 0.2;
parameters.kAtMostSameBy = 0.50;
} }
// 20km // 20km
else if (distance < 20000.) else if (distance < 20000.)
{ {
parameters.kAlternativesToUnpackFactor = 8.0; parameters.kAlternativesToUnpackFactor = 8.0;
parameters.kCellsAtLeastDifferentBy = 1.0; parameters.kCellsAtMostSameBy = 1.0;
parameters.kAtLeastOptimalAroundViaBy = 0.2; parameters.kAtLeastOptimalAroundViaBy = 0.2;
parameters.kAtMostSameBy = 0.60;
} }
// 50km // 50km
else if (distance < 50000.) else if (distance < 50000.)
{ {
parameters.kAlternativesToUnpackFactor = 6.0; parameters.kAlternativesToUnpackFactor = 6.0;
parameters.kCellsAtLeastDifferentBy = 0.95; parameters.kCellsAtMostSameBy = 0.95;
parameters.kAtMostSameBy = 0.70;
} }
// 100km // 100km
else if (distance < 100000.) else if (distance < 100000.)
{ {
parameters.kAlternativesToUnpackFactor = 4.0; parameters.kAlternativesToUnpackFactor = 4.0;
parameters.kCellsAtLeastDifferentBy = 0.75; parameters.kCellsAtMostSameBy = 0.75;
} }
return parameters; return parameters;
@ -256,7 +259,7 @@ RandIt filterPackedPathsByCellSharing(RandIt first,
const Parameters &parameters) const Parameters &parameters)
{ {
// In this case we don't need to calculate sharing, because it would not filter anything // In this case we don't need to calculate sharing, because it would not filter anything
if (parameters.kCellsAtLeastDifferentBy >= 1.0) if (parameters.kCellsAtMostSameBy >= 1.0)
return last; return last;
util::static_assert_iter_category<RandIt, std::random_access_iterator_tag>(); util::static_assert_iter_category<RandIt, std::random_access_iterator_tag>();
@ -311,7 +314,7 @@ RandIt filterPackedPathsByCellSharing(RandIt first,
const auto sharing = 1. - difference; const auto sharing = 1. - difference;
if (sharing > parameters.kCellsAtLeastDifferentBy) if (sharing > parameters.kCellsAtMostSameBy)
{ {
return true; return true;
} }
@ -491,7 +494,7 @@ RandIt filterUnpackedPathsBySharing(RandIt first,
BOOST_ASSERT(sharing >= 0.); BOOST_ASSERT(sharing >= 0.);
BOOST_ASSERT(sharing <= 1.); BOOST_ASSERT(sharing <= 1.);
if (sharing > parameters.kAtLeastDifferentBy) if (sharing > parameters.kAtMostSameBy)
{ {
return true; return true;
} }