From 2fee030a26996a167adbf28f96fca8c4fd749005 Mon Sep 17 00:00:00 2001 From: Jonathan G Rennison Date: Tue, 14 Jan 2020 03:11:57 +0000 Subject: [PATCH] Change: Algorithm for transfer feeder payments The original algorithm pays intermediate legs in feeder systems based on the start and end stations of that particular leg. This tends to result in large negative payments on the final leg for journeys with many feeder legs, as the overall feeder payment increases with the number of legs, and the final leg is penalised for discrepancies between the previous leg payments and the actual payment for delivery from the source to the destination. The feeder share setting is a partial mitigation, however it is difficult to tune as a suitable value depends on the number of legs and the network topology, which are often not the same for all vehicles. The new incremental algorithm pays the cargo payment from the source station to the end station of the current leg, minus any previous transfer feeder payments for each leg. This prevents unbounded increase of feeder payments and therefore avoids the issue of excessive negative payments on the final leg. Feeder payments may be negative, e.g. in the case of poorly performing or highly indirect legs. This is better than penalising the final leg. This mode reduces the need to tune the feeder shares setting to the current network. The feeder share setting applies in the existing way. --- src/economy.cpp | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/src/economy.cpp b/src/economy.cpp index a0907efbe9..00bdd6f534 100644 --- a/src/economy.cpp +++ b/src/economy.cpp @@ -1216,10 +1216,11 @@ void CargoPayment::PayFinalDelivery(const CargoPacket *cp, uint count) */ Money CargoPayment::PayTransfer(const CargoPacket *cp, uint count) { - Money profit = GetTransportedGoodsIncome( + Money profit = -cp->FeederShare(count) + GetTransportedGoodsIncome( count, - /* pay transfer vehicle for only the part of transfer it has done: ie. cargo_loaded_at_xy to here */ - DistanceManhattan(cp->LoadedAtXY(), Station::Get(this->current_station)->xy), + /* pay transfer vehicle the difference between the payment for the journey from + * the source to the current point, and the sum of the previous transfer payments */ + DistanceManhattan(cp->SourceStationXY(), Station::Get(this->current_station)->xy), cp->DaysInTransit(), this->ct);