Timetable Analyser...

I'd noticed previously that you get different sets (or orders) of results for different sort options in the timetable window, but had put it down to the analyser performing the analysis in different orders. But to have it give some warnings and omit them entirely in other instances is somewhat worrying?

Back to the analyser (although Liverpool St - Shenfield or beyond 1949 is definitely interesting !). I am getting different analyser outputs depending on sort order of the trains.

…

Timetable attached,

Found something else that I don't understand.

1B01/$1B01[60.2]{[seedgroup]=04:45}: Associated train 1B16/$1B16 not defined at Edinburgh Waverley
1B01/$1B01[60.2]{[seedgroup]=04:45}: Length 45m not the same as next working 5M16/$5M16[700.2]{[seedgroup]=04:45} at Edinburgh Waverley (45m vs 176m)

1B01 is the Up Fort William sleeper that enters from Polmont Jn at 00:27 and after the various shunts and joins runs forward as 1M16 to Carstairs going off sim at 01:41. There is neither 1B01 nor 5M16 in the 04:45 seed group.

What could be causing that report?

Found something else that I don't understand.

1B01/$1B01[60.2]{[seedgroup]=04:45}: Associated train 1B16/$1B16 not defined at Edinburgh Waverley
1B01/$1B01[60.2]{[seedgroup]=04:45}: Length 45m not the same as next working 5M16/$5M16[700.2]{[seedgroup]=04:45} at Edinburgh Waverley (45m vs 176m)

1B01 is the Up Fort William sleeper that enters from Polmont Jn at 00:27 and after the various shunts and joins runs forward as 1M16 to Carstairs going off sim at 01:41. There is neither 1B01 nor 5M16 in the 04:45 seed group.

What could be causing that report?

Okay, it's a genuine error in the timetable. 1B01 runs irrespective of which seed group you start with, but 1B16 only starts if you select the "TT start" seed group. So if you start the 04:45 seed group, 1B01 runs but 1B16 doesn't, so the timetable goes wrong.

clive in post 134786 said:

Okay, it's a genuine error in the timetable. 1B01 runs irrespective of which seed group you start with, but 1B16 only starts if you select the "TT start" seed group. So if you start the 04:45 seed group, 1B01 runs but 1B16 doesn't, so the timetable goes wrong.

Sorry, you've lost me. In actual practice the TT does not go wrong - or at least it never did when I was testing and there have been no reports on the Forum or Mantis recording any TT errors.

If you start the 04:45 seed group, 1B01 does not run because the 04:45 seed group starts the session at 04:45 which means that 1B01 cannot enter as it was due to enter before 04:45

I may be misremembering, but I recall I once had a train enter from before the seed time, because it had a full hour of delay. So I believe in the wrong circumstances, the Edinburgh TT may well be wrong.

Dionysusnu in post 134797 said:

I may be misremembering, but I recall I once had a train enter from before the seed time, because it had a full hour of delay. So I believe in the wrong circumstances, the Edinburgh TT may well be wrong.

I'm afraid we will have to differ there. No matter when the train actually enters, it is always timetabled to enter at a specific time. If you have a train enter at the wrong time, that is a function of the core code and not the timetable. The timetable is not wrong even if the core code is applying it in a way that you think is wrong.

postal in post 134806 said:

Dionysusnu in post 134797 said:

I may be misremembering, but I recall I once had a train enter from before the seed time, because it had a full hour of delay. So I believe in the wrong circumstances, the Edinburgh TT may well be wrong.

I'm afraid we will have to differ there. No matter when the train actually enters, it is always timetabled to enter at a specific time. If you have a train enter at the wrong time, that is a function of the core code and not the timetable. The timetable is not wrong even if the core code is applying it in a way that you think is wrong.

If the core code enters that train because it is delayed, it will infinitely wait for a train that isn't seeded. You could put blame on either of the two parts.

bill_gensheet in post 134637 said:

Back to the analyser (although Liverpool St - Shenfield or beyond 1949 is definitely interesting !). I am getting different analyser outputs depending on sort order of the trains.

…

Timetable attached,

That was, um, interesting. When I analysed it with the detailed reports added, I found a FRI train was waiting for a WED train! Which immediately pointed at the area of the code to be suspicious of.

It turns out there are *two* bugs in different parts of the code that makes sure instances of associated trains have the same decisions made. In all my testing, these two bugs had cancelled each other out and so I never spotted it. But your example tickled one but not the other! (As you might guess, the different order of analysis means that the bug wasn't triggered when sorted differently.) Fixing both means the problem goes away and that timetable doesn't produce any warnings.
The fix is now in the core code and so will appear in the next release. It's quite possible that it will improve things for others as well (<cough> VInce <cough>).
Thanks for taking the time to create this minimal timetable.

postal in post 134788 said:

If you start the 04:45 seed group, 1B01 does not run because the 04:45 seed group starts the session at 04:45 which means that 1B01 cannot enter as it was due to enter before 04:45

Argh. If I ever knew that, I'd forgotten it and it's not mentioned in the wiki page about seeding groups. That's right (I've just found the code that does it) and that means another bug in the analyser.

Mantis 32532 raised.