> This randomness calculation should be off when we use --random false.
No. This is not what option --random does.
Please see https://sumo.dlr.de/docs/Simulation/Randomness.html
As long as vehicles have sigma > 0 (default is 0.5) there will be random
speed fluctuations between your partitions.

Am Mi., 22. Feb. 2023 um 14:23 Uhr schrieb Mahima <[email protected]>:

> Hi,
>
> We have developed a parallel framework over SUMO. When I am copying
> vehicles from one partition to another. With the vehicles I am also copying
> the following lane change parameters. I am keeping sigma 0, --random false
> and same seed value for all the partitions and sequential SUMO.
>
> "laneChangeModel.speedGainProbabilityRight"
> "laneChangeModel.keepRightProbability"
> "laneChangeModel.lookAheadSpeed"
>
> After adding vehicles in the next partition, I am also moving them for the
> desired position in the current step and setting speed for the current
> step.
> i am calculating the current step speed as follows:
>
> double vthis=LastTimestepSpeed+ACCEL2SPEED(LastTimestepAcceleration);
> Or if the vehicle has a Leader...then with the follow speed.
>
> But if I compare travel time of this parallel framework with sequential
> SUMO, I am getting an accuracy error.
>
> I have found that patchSpeedBeforeLC is calculating some different speed
> which is causing randomness.
>
>   vDawdle = MAX2(vMin, dawdle2(vMax, sigma, veh->getRNG()));
>
> This randomness calculation should be off when we use --random false.
>
> Thanks,
> Mahima
>
> On Wed, Feb 22, 2023 at 1:41 PM Jakob Erdmann <[email protected]>
> wrote:
>
>> The function getStopSpeed is not only used for <stop> elements but also
>> for approaching intersections where a vehicle needs to come to a stop.
>> From your description it is not clear what exactly you are doing and why
>> you are observing a differences between some speeds and some other speeds.
>>
>>
>> Am Di., 21. Feb. 2023 um 14:24 Uhr schrieb Mahima <[email protected]>:
>>
>>> Thanks for your reply.
>>> Yes, sigma is already set as 0. The only difference I can see is the
>>> stop speed (getStopSpeed) is different.
>>>
>>> How can I set the stop speed of a vehicle? Is it by using
>>> libsumo::Vehicle::setStopParameter? But then I need to define the stop
>>> first...correct?
>>>
>>> Thanks.
>>>
>>> On Sun, Feb 19, 2023 at 3:28 PM Jakob Erdmann <[email protected]>
>>> wrote:
>>>
>>>> > Why does the vehicle need information about the vehicle on the
>>>> previous edge for the car following model speed calculation?
>>>> This is likely a misunderstanding. What gives you that impression?
>>>>
>>>> > How can I set the car following model parameters from the previous
>>>> partition to the master partition such that it gives the same speed
>>>> calculation of a vehicle?
>>>> The default car-following model doesn't have internal state so it
>>>> should reproduce the same behavior when faced with the same situation
>>>> (distance, ego speed, leader speed, deceleration capabilities,
>>>> speedFactor). A possible cause for difference is the random component
>>>> (sigma). You can check whether the differences are due to randomness by
>>>> setting sigma=0.
>>>>
>>>> Am So., 19. Feb. 2023 um 11:36 Uhr schrieb Mahima <[email protected]>:
>>>>
>>>>> Hi,
>>>>>
>>>>> Why does the vehicle need information about the vehicle on the
>>>>> previous edge for the car following model speed calculation?
>>>>> How can I set the car following model parameters from the previous
>>>>> partition to the master partition such that it gives the same speed
>>>>> calculation of a vehicle?
>>>>>
>>>>> Thanks
>>>>>
>>>>> On Wed, Sep 28, 2022 at 9:48 AM Jakob Erdmann <[email protected]>
>>>>> wrote:
>>>>>
>>>>>> using getParameter / setParameter with the following values should be
>>>>>> enough for the default lanechangem model:
>>>>>> "laneChangeModel.speedGainProbabilityRight"
>>>>>> "laneChangeModel.keepRightProbability"
>>>>>> "laneChangeModel.lookAheadSpeed"
>>>>>>
>>>>>> Am Mo., 26. Sept. 2022 um 09:58 Uhr schrieb Mahima <
>>>>>> [email protected]>:
>>>>>>
>>>>>>> When I am copying a vehicle from one partition to the other on the
>>>>>>> same lane and position as it was on the previous partition, but in the
>>>>>>> current timestep if there was a lane change decision in the previous
>>>>>>> partition......which lane change API or flag will give me the same lane
>>>>>>> change decision in the master partition.
>>>>>>> In this scenario, I am already making sure that the neighbouring
>>>>>>> vehicles for this vehicle are the same as on the previous partition.
>>>>>>>
>>>>>>> Please suggest.
>>>>>>>
>>>>>>> On Mon, Sep 26, 2022 at 9:39 AM Jakob Erdmann <[email protected]>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> No. TraCI runs before the computation of this step's values (
>>>>>>>> https://sumo.dlr.de/docs/Developer/Implementation_Notes/Simulation_Loop.html#main_vehicle_update_loop
>>>>>>>> )
>>>>>>>>
>>>>>>>> Am So., 25. Sept. 2022 um 11:02 Uhr schrieb Mahima <
>>>>>>>> [email protected]>:
>>>>>>>>
>>>>>>>>> Hi,
>>>>>>>>>
>>>>>>>>> Is there any way to read the vehicle's speed, lane and position in
>>>>>>>>> the current timestep?
>>>>>>>>>
>>>>>>>>> libsumo::Vehicle::getLanePosition
>>>>>>>>> libsumo::Vehicle::getSpeed
>>>>>>>>> All these APIs, give information about the last timestep.
>>>>>>>>>
>>>>>>>>> Thanks
>>>>>>>>> _______________________________________________
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