Page 1 of 1
| Deciding between trains entering from different sims 30/09/2018 at 22:45 #112389 | |
postal
5190 posts |
Here's a tricky one which has got me stumped. Working on a Motherwell TT and a train from Mossend needs traction. This could come from either Corkerhill or Motherwell. It is easy to set that up within the Motherwell sim using an "are alternatives" rule or a decision. The problem arises if Motherwell is chained to Edinburgh. If we assume there is an equal chance of the loco coming from either Corkerhill or Millerhill then it would be easy to set the %age chance of running from Millerhill in the Edinburgh sim to 50% and that would give some sort of consistency between Edinburgh and Motherwell. However, if the loco enters the sim at Millerhill, is there any way to link that to the Motherwell sim so that the loco from Corkerhill does not enter? It can't be fudged with a mutually exclusive or must not run rule as the loco from Corkerhill enters at Rutherglen at 12:25 while the loco from Millerhill doesn't enter at Midcalder until 12:38. If the loco is in the Edinburgh sim, it will enter at Midcalder no matter what rules have been set internally in the Motherwell sim. The problem will get harder again to resolve if a Glasgow sim ever sees the light of day because there will be exactly the same problem about the entry at Corkerhill. Is there anything I have missed which could give a sensible operation when the sims are chained? “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Last edited: 30/09/2018 at 22:46 by postal Reason: None given Log in to reply |
| Deciding between traisn entering from different sims 30/09/2018 at 23:10 #112390 | |
58050
2650 posts |
Is this a ficticious timetable John? Cos if it's modern day then subject to the TOC/FOC would largelt depend on which Company stables it's locos & where & if it's in the BR era then it could come from pretty much anywhere, but Corkerhill in BR days was predominantly AC eletric locos stabled there.
Log in to reply |
| Deciding between traisn entering from different sims 30/09/2018 at 23:20 #112391 | |
|
postal
5190 posts |
58050 in post 112390 said:Is this a ficticious timetable John? Cos if it's modern day then subject to the TOC/FOC would largelt depend on which Company stables it's locos & where & if it's in the BR era then it could come from pretty much anywhere, but Corkerhill in BR days was predominantly AC eletric locos stabled there.Although I've used an example from a sample TT, the detail is not really relevant to the core question. Is it possible to control entries from other sims so that you don't have two trains trying to fulfil the same function? “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Log in to reply |
| Deciding between traisn entering from different sims 30/09/2018 at 23:30 #112392 | |
|
58050
2650 posts |
postal in post 112391 said:58050 in post 112390 said:I'd probably say at present doing it the way you suggest wwith a '%' variable on both light locomotive wschedule with 'an alternatives' rule to boot. Can't think of any opther way except for one way I was thinking of timetabling assisting locos in the York 1991 timetables for trains that had failed & requesting assistance. I'll use my idea on that for an example here:-Is this a ficticious timetable John? Cos if it's modern day then subject to the TOC/FOC would largelt depend on which Company stables it's locos & where & if it's in the BR era then it could come from pretty much anywhere, but Corkerhill in BR days was predominantly AC eletric locos stabled there.Although I've used an example from a sample TT, the detail is not really relevant to the core question. Is it possible to control entries from other sims so that you don't have two trains trying to fulfil the same function? I was going to create 4 or 5 different schedules in the York timetable for assisting locos. One schedule for a loco coming from Doncaster, another one coming from Knottingley, another one coming from Leeds & another schedule off York LHS. On the decision I'd give a different number for each schedule which would govern which ones are likely to appear the most to which one was likely to appear the least & then if a train failed & assistance was requested then the 'decision' would pick one of the schdules. You could do something similar with your quiery regarding locos entering from other sims. Log in to reply |
| Deciding between traisn entering from different sims 01/10/2018 at 01:44 #112393 | |
|
postal
5190 posts |
58050 in post 112392 said:I was going to create 4 or 5 different schedules in the York timetable for assisting locos. One schedule for a loco coming from Doncaster, another one coming from Knottingley, another one coming from Leeds & another schedule off York LHS. On the decision I'd give a different number for each schedule which would govern which ones are likely to appear the most to which one was likely to appear the least & then if a train failed & assistance was requested then the 'decision' would pick one of the schdules. You could do something similar with your quiery regarding locos entering from other sims.That's where the problem starts. It is not in the individual TT, it is when TTs are chained together. Suppose you had a train at Taunton Yard that needed traction and that the traction might come from Westbury or Bristol. In the Exeter TT you can put a decision in so that one or other LD will enter. What happens if you are chained to Bristol, Westbury or both? If you just put a 50% chance of the LD entering the Bristol TT and similar for the Westbury TT then there are 4 possible scenarios. 1) You have 2 LDs turning up at Cogload (if the 50% chance in the Bristol TT made that loco enter and the 50% chance in the Westbury TT made that one enter as well). 2) You have 1 LD turn up from Bristol as that 50% chance fell in favour of the loco entry while the Westbury 50% caused the loco not to enter. 3) You have 1 LD turn up from Westbury as that 50% chance fell in favour of the loco entry while the Bristol 50% caused the loco not to enter. 4) No LD turns up at all as both Bristol and Westbury 50% chances fell on the non-entry side. So you have a 25% chance of two LD arriving, 50% chance that one LD will arrive and 25% chance that no LD will arrive. If you are only chained to one of the two sims, there will be a similar sort of scenario again with the same percentage chances of 0,1 or 2 LDs entering. Can anyone see a way round that? “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Log in to reply |
| Deciding between traisn entering from different sims 01/10/2018 at 05:15 #112394 | |
GeoffM
6282 posts 
|
There is currently no way to handle this. It needs a master timetabling application that talks to all the Sims to ensure only one entity ever runs. It's been talked about before but so long ago I can't even remember where.
SimSig Boss Log in to reply The following user said thank you: postal |
| Deciding between traisn entering from different sims 01/10/2018 at 09:19 #112397 | |
|
postal
5190 posts |
GeoffM in post 112394 said:There is currently no way to handle this. It needs a master timetabling application that talks to all the Sims to ensure only one entity ever runs. It's been talked about before but so long ago I can't even remember where.Geoff Thanks. I was afraid that was the answer! “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Log in to reply |
| Deciding between traisn entering from different sims 01/10/2018 at 09:31 #112398 | |
Humorist
102 posts |
postal in post 112389 said:Here's a tricky one which has got me stumped. Working on a Motherwell TT and a train from Mossend needs traction. This could come from either Corkerhill or Motherwell. It is easy to set that up within the Motherwell sim using an "are alternatives" rule or a decision. The problem arises if Motherwell is chained to Edinburgh.Only a small point, but I think that locomotives were at Shields Road, and Corkerhill only served multiple units, both diesel and electric, I think. Any Glaswegians on the forum could put me right if this is incorrect. Log in to reply |
| Deciding between traisn entering from different sims 01/10/2018 at 09:58 #112399 | |
Steamer
3921 posts |
One way of doing it would be to send a train from Motherwell to Edinburgh (and Glasgow, should it ever be developed) at the start of the simulation, with decisions in place to send different variants of the train depending on different decision outcomes. Then, use rules on Edinburgh (and a hypothetical Glasgow simulation) to govern the entry of the loco at Corkerhill/Millerhill. Obviously, that only works if you have a centrally-located 'master' simulation within the set of simulations you want to chain to. "Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q) Log in to reply The following user said thank you: postal |
| Deciding between traisn entering from different sims 01/10/2018 at 11:03 #112401 | |
|
postal
5190 posts |
Humorist in post 112398 said:Only a small point, but I think that locomotives were at Shields Road, and Corkerhill only served multiple units, both diesel and electric, I think. Any Glaswegians on the forum could put me right if this is incorrect.It's the principle of the thing rather than the fine detail that is bothering me at the moment but thanks anyway. “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Log in to reply |
| Deciding between traisn entering from different sims 01/10/2018 at 15:09 #112406 | |
Peter Bennet
5360 posts |
Humorist in post 112398 said:I'm not a Glaswegian but that is correct, though the hypothesis was for illustrative purposes only I believe. Peter I identify as half man half biscuit - crumbs! Log in to reply The following user said thank you: postal |
| Deciding between traisn entering from different sims 01/10/2018 at 18:17 #112408 | |
|
GeoffM
6282 posts
|
Steamer in post 112399 said:One way of doing it would be to send a train from Motherwell to Edinburgh (and Glasgow, should it ever be developed) at the start of the simulation, with decisions in place to send different variants of the train depending on different decision outcomes. Then, use rules on Edinburgh (and a hypothetical Glasgow simulation) to govern the entry of the loco at Corkerhill/Millerhill.I don't think that works in scenarios where sims A and B are chained to sim X where either sim A or sim B sends a train on a common path to sim X (eg a WTT "Y" path). Sim A and sim B don't talk to each other so have no way of knowing whether the other sim has entered their version of the common train. That's just a simple example: there are other situations where many sims are involved potentially. SimSig Boss Log in to reply |
| Deciding between traisn entering from different sims 01/10/2018 at 18:46 #112409 | |
|
Hawk777
386 posts |
It could be made to work in that situation, though it would be a bit ugly. Sim X would decide whether the train should come from A or B. Then at the beginning of the TT, X would send fake trains to A and B for the purpose of communicating this decision. Perhaps X would send a fake train to A if it wanted A to supply the later real train, or to B if it wanted B to supply the later real train. Each of A and B would have a rule that the real train not enter until the relevant number of minutes after the corresponding fake train, and would give the real train 100% chance. Then exactly one of A or B would receive the fake train from X at startup, so exactly one of A or B’s rule would be satisfied, so exactly one of A or B’s real trains would run.
Log in to reply The following user said thank you: postal |
| Deciding between traisn entering from different sims 01/10/2018 at 19:22 #112410 | |
|
Steamer
3921 posts |
GeoffM in post 112408 said:Steamer in post 112399 said:That's why simulation X sends different versions of a train to A and B at the start of the timetable; sim A sends the common train if variant 1 enters from X shortly after the timetable starts, and doesn't send it if variant 2 enters. Similarly, simulation B doesn't send the common train if it receives variant 1, but does if it receives variant 2. These variants can be seeded on start-up close to the simulation fringe. I accept that the complexity increases exponentially as the number of simulations and possible common trains increases.One way of doing it would be to send a train from Motherwell to Edinburgh (and Glasgow, should it ever be developed) at the start of the simulation, with decisions in place to send different variants of the train depending on different decision outcomes. Then, use rules on Edinburgh (and a hypothetical Glasgow simulation) to govern the entry of the loco at Corkerhill/Millerhill.I don't think that works in scenarios where sims A and B are chained to sim X where either sim A or sim B sends a train on a common path to sim X (eg a WTT "Y" path). Sim A and sim B don't talk to each other so have no way of knowing whether the other sim has entered their version of the common train. That's just a simple example: there are other situations where many sims are involved potentially. EDIT: Hawk described it better than I did. "Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q) Last edited: 01/10/2018 at 19:23 by Steamer Reason: None given Log in to reply The following user said thank you: postal |
| Deciding between traisn entering from different sims 01/10/2018 at 20:56 #112411 | |
|
postal
5190 posts |
As ever, the ingenuity of SimSig TT writers finds ways to provide functionality far beyond what was envisaged when the core code was written. Thanks, guys. “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Last edited: 01/10/2018 at 23:35 by postal Reason: None given Log in to reply |
| Deciding between traisn entering from different sims 01/10/2018 at 21:00 #112412 | |
|
GeoffM
6282 posts
|
Hawk777 in post 112409 said:It could be made to work in that situation, though it would be a bit ugly. Sim X would decide whether the train should come from A or B. Then at the beginning of the TT, X would send fake trains to A and B for the purpose of communicating this decision. Perhaps X would send a fake train to A if it wanted A to supply the later real train, or to B if it wanted B to supply the later real train. Each of A and B would have a rule that the real train not enter until the relevant number of minutes after the corresponding fake train, and would give the real train 100% chance. Then exactly one of A or B would receive the fake train from X at startup, so exactly one of A or B’s rule would be satisfied, so exactly one of A or B’s real trains would run.But you've gone from two possible real trains to one real and one fake train, netting you a saving of zero trains. Add to that two fake schedules for X. It also only covers the simplest case of A->X<-B, not the plethora of other possible combinations. SimSig Boss Last edited: 01/10/2018 at 21:03 by GeoffM Reason: None given Log in to reply |
| Deciding between traisn entering from different sims 01/10/2018 at 23:44 #112413 | |
|
postal
5190 posts |
GeoffM in post 112412 said:But you've gone from two possible real trains to one real and one fake train, netting you a saving of zero trains. Add to that two fake schedules for X. It also only covers the simplest case of A->X<-B, not the plethora of other possible combinations.Agreed that it is not elegant and introduces things which are not from real life but it does enable a problem to be worked round if anyone so desires. No doubt similar (if more complex) solutions could produce work-rounds for the more complicated scenarios that could occur. There have always been fudges and work-rounds and as the core code has become more sophisticated the early work-rounds are now redundant but fudges are being found for more complicated problems. After all it is not so many years ago that we had passenger trains entering the sim from all sorts of goods yards and depots because the core code hadn't got as far as seeding trains. Long may the core code continue to improve and long may the ingenuity of developers and TT writers push the boundaries of those improvements. “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Log in to reply |
| Deciding between traisn entering from different sims 02/10/2018 at 07:39 #112414 | |
Meld
1098 posts |
Interesting discussion guys, this issue first raised its ugly head for me doing the Leamington TTs for Karl. We have a Birch Coppice - Southampton liner with variable paths to Leamington, ie via Landor St or Nuneaton/Cov now a decision in Leamington & Saltley can decide which one runs - Easy. Lets take this chain example Cov -Leam - Marylebone & Oxford. The train enters Leanington from Landor St @ 0814 but enters from Cov @ 0827 even with the ideas above you could still finish up with both entering. Maybe it would be better for the Master host sim to send decisions back to previous sims eg Leamington decides which version of the train is to run the sends back to Cov of which version is to run. Or do we have a multiple decision layer with Critical Master decisions that apply to one sim, overriding the decisions in any other chained sim Food for thought Passed the age to be doing 'Spoon Feeding' !!! Last edited: 02/10/2018 at 07:44 by Meld Reason: None given Log in to reply |
| Deciding between traisn entering from different sims 02/10/2018 at 11:53 #112416 | |
|
kbarber
1712 posts |
Meld in post 112414 said:Interesting discussion guys, this issue first raised its ugly head for me doing the Leamington TTs for Karl.But would having one 'master sim' work if you had a similar situation at the other edge of our hypothetical 'Motherwell'? If the originating sim and everything in between are part of the chain, it's easy enough; originating sim makes the decision. If the originating sim is in the chain but one possible route isn't simulated, there needs to be a way the originating sim communicates (presumably through hypothetical Motherwell) back to the fringe downstream of the gap. If the originating sim isn't in the chain, there needs to be a way for the farthest-upstream sim where the earliest entry of an alternative would take place to communicate through hypothetical Motherwell back to the other entry point. Could it work? My non-programmer's mind comes up with a few thoughts; it would need both some core code development and some additional work by timetable developers. If there were a method for sims to communicate timetable information both ways in advance of trains running, scenario 2 could be dealt with by an 'are alternatives' rule checking forward to see which sims are in play, and each sim receiving such a message then checking back through all the other sims. I imagine it wouldn't be too difficult to send timetable locations as part of the message. It would also be necessary to send timetable details of the alternative. Then a sim receiving such a message from one chained sim would have to check back along the chain the other way. Final bit is that, if the train running through the complete chain is selected, the entry on the incomplete side is suppressed (or vice versa). In this scenario, the tt developer might not need to do anything at all. If the originating point isn't in the chain, it should still work OK. It's rather unlikely, I would think, that both alternatives would be scheduled to enter their separate sims at the same time. (Having said that, what's the betting the first time this is tried we'll find exactly that? But I digress.) When building a timetable for chaining, the tt developer would need to include in each affected timetable some basic information for the alternative, sufficient for the same 'are alternatives message' to go forward to the common sim then be sent back up the other leg. That would have to be done for every such train in every affected sim - a train entering from Saltley would surely be in the Saltley sim before its booked entry to Coventry, but if Saltley weren't part of the chain Coventry would need to decide whether it entered Leamington from the Saltley fringe. What I don't know is quite how much bandwidth these kind of messages would be likely to consume, nor how easy it would be to alter the core code so that a decision in another sim that wasn't directly chained could override whatever decision a sim was going to make. Provided the necessary bandwidth wasn't too great, there shouldn't be a need to suppress any of these messages - just need to ensure the redundant ones are discarded (or that they never conflict with what's already decided). Clive (and Geoff when you've a moment): any thoughts? Log in to reply The following user said thank you: Meld |
| Deciding between traisn entering from different sims 02/10/2018 at 15:19 #112425 | |
|
clive
2738 posts |
Mantis 21718 raised. I have some ideas in my head but I need to sanity-check them before writing them down. But, very roughly, what I have in mind is along the lines of: * When a decision is made, it is notified to all chained sims. * When a sim joins a chain, committed decisions are passed to it. * There is a way to refer to a remote decision. Don't hold your breath - I've got a lot in the queue. Log in to reply The following user said thank you: postal |
| Deciding between traisn entering from different sims 03/10/2018 at 02:21 #112442 | |
|
Hawk777
386 posts |
clive in post 112425 said:Mantis 21718 raised.Seems like one could give each decision a name. When a chain is set up, if there are decisions with the same name in multiple sims in the chain, they all make the same decision. Then a TT for sim A could be written with a decision in it such that a loco enters there only if the decision goes its way, similarly a TT for sim B, and a TT for sim X could have the same decision choosing between entries of locos at the two fringes. That way: * If you’re playing only A (or only B), the decision fires and determines whether a loco enters on your sim or not, which is realistic (sometimes it will and sometimes it won’t because it will come from the other one). * If you’re playing only X, the decision fires and determines whether the loco comes from the fringe to A or the fringe to B, which is realistic. * If you’re playing X with A and B chained, the decision fires and determines whether the loco enters within A or within B, after which it makes its way to X, which is realistic, and the rules about the fringes are ignored because TT entries from chained fringes are ignored in favour of the trains actually coming from the chained sims. * If you’re playing X with A but not B chained, the decision fires and determines whether the loco enters within A or at the B fringe on X, which is realistic. It might be necessary to name each of the possible outcomes, not just the decision as a whole, because the outcomes would have different actions associated with them in different TTs for different sims. In this example, say, in the TT for A, the decision would be between (1) “loco enters at yard” and (2) “loco does not enter”; in the TT for B, the decision would be between (1) “loco does not enter” and (2) “loco enters at yard”; and in the TT for X, the decision would be between (1) “loco enters at fringe to A” and (2) “loco enters at fringe to B”. So one might need to name the outcomes, to make sure that either all the (1)s are chosen or all the (2)s are chosen and not a mix thereof. Log in to reply |