Hi Jakob,

ah, obviously itself is in there always, I was too blind to see that, because I 
always filtered out the ego vehicle in the results. Still good, if the empty 
subscription results in a more “forgiving” behavior. Thanks a lot!

Jakob

Von: [email protected] [mailto:[email protected]] Im 
Auftrag von Jakob Erdmann
Gesendet: Freitag, 5. Januar 2018 10:24
An: Sumo project User discussions <[email protected]>
Betreff: Re: [sumo-user] Context Subscription of a Vehicle to Values of Persons 
(TraCI API C++)

Hello Jakob,
the error was caused when trying to access an empty result (no objects in 
range). Since a vehicle always has itself in range, the problem never occurred 
in the first case. It should be fixed in the latest development version 335d5a7.
regards,
Jakob

2018-01-05 9:44 GMT+01:00 Kaths, Jakob 
<[email protected]<mailto:[email protected]>>:
Hi,

I retried with today’s nightly snapshot (0_32_0_+0080-45b239f71c) and get the 
same behavior, except I can now catch a tcpip::SocketException (somehow didn’t 
work in my larger code) and avoid the crash.

Maybe I got you wrong, but retrieving an empty vehicle subscription works fine 
and without throwing an exception for me (I used the example you provided with 
the Python test and with 100m radius, at times there are no vehicles and no 
persons). When subscribing only to persons though, the exception is thrown as 
soon as I retrieve the results with 
“traci.simulation.getContextSubscriptionResults("ego");” when there is no 
person around.
So to me it seems that
traci.simulation.subscribeContext(CMD_SUBSCRIBE_VEHICLE_CONTEXT, "ego", 
startTime, endTime, CMD_GET_VEHICLE_VARIABLE, subscription_radius, 
egoSubscriptionVarsVeh);
and
traci.simulation.subscribeContext(CMD_SUBSCRIBE_VEHICLE_CONTEXT, "ego", 
startTime, endTime, CMD_GET_PERSON_VARIABLE, subscription_radius, 
egoSubscriptionVarsPed);
have a different behavior when there are no results. I’m not sure if that’s 
intended, but it did confuse me since I thought I could just exchange 
CMD_GET_VEHICLE_VARIABLE by CMD_GET_PERSON_VARIABLE.

If you still need them, I would like to provide the stack traces, but I don’t 
know how to create them unfortunately. Would StackWalker be the right tool?

Thanks

Jakob



Von: [email protected]<mailto:[email protected]> 
[mailto:[email protected]<mailto:[email protected]>] Im 
Auftrag von Jakob Erdmann
Gesendet: Donnerstag, 4. Januar 2018 16:28

An: Sumo project User discussions 
<[email protected]<mailto:[email protected]>>
Betreff: Re: [sumo-user] Context Subscription of a Vehicle to Values of Persons 
(TraCI API C++)

Possibly you are trying to retrieve context subscription results when there 
aren't any.  The client throws Exceptions without any error message in this 
case (helpful messages added in the development version). This was the only way 
I could reproduce an error.
Please see if you get a better error with the development version. Otherwise I 
need at least the stack traces from your crash (client and server).

regards,
Jakob

2018-01-03 17:30 GMT+01:00 Kaths, Jakob 
<[email protected]<mailto:[email protected]>>:
Hey,

thanks a lot for your answer. I checked the Python example and adapted it to my 
needs and it worked. I then prepared the minimal example for C++ and while 
doing that, I think I found the solution. However, I still didn’t fully 
understand why… Maybe you could give me a little hint, just for understanding. 
My subscription to both vehicles and persons around a vehicle works fine now. 
If I only subscribe to persons though, the program crashes straight after 
starting it. So, if I comment line 66 it crashes (which is what I did in my 
not-minimal-example and why I asked for help), if I comment line 67 it works 
and if I don’t comment either of those two lines, it works, too.

You can find the cpp-file here:
https://syncandshare.lrz.de/dl/fiWxH8FERhgLwXaDorAyFmW1/SumoConnect.cpp

Thanks for the amazing help here!

Jakob Kaths


Von: [email protected]<mailto:[email protected]> 
[mailto:[email protected]<mailto:[email protected]>] Im 
Auftrag von Jakob Erdmann
Gesendet: Mittwoch, 20. Dezember 2017 09:32
An: Sumo project User discussions 
<[email protected]<mailto:[email protected]>>
Betreff: Re: [sumo-user] Context Subscription of a Vehicle to Values of Persons 
(TraCI API C++)

Hello,
subscribing to persons around an object and subscribing to things around a 
person should be working. (at least it does in our tests since version 0.31.0).
You may take a look at the tests at 
https://github.com/DLR-TS/sumo/tree/master/tests/complex/traci/contextSubscriptions
Can send a small scenario where it fails for you?
regards,
Jakob

2017-12-19 17:59 GMT+01:00 Kaths, Jakob 
<[email protected]<mailto:[email protected]>>:
Hello!

I was wondering if it’s possible to retrieve values of pedestrians in SUMO by 
subscription. I know, that in Context Subscription in the Wiki 
(http://sumo.dlr.de/wiki/TraCI/Object_Context_Subscription) pedestrians are not 
mentioned. However, I found the corresponding value (CMD_GET_PERSON_VARIABLE 
0xae) in the TraCIConstants.h and tried to subscribe, but it failed. Is there a 
possibility to retrieve position, angle, speed etc. from pedestrians via 
subscription without modelling them as vehicles? If not, is this planned for 
the future or could you give a hint of how to implement this?

Thanks in advance!

Jakob


--
Dipl.-Ing. Jakob Kaths

Technische Universität München
Ingenieurfakultät Bau Geo Umwelt
Lehrstuhl für Verkehrstechnik
[email protected]<mailto:[email protected]>


_______________________________________________
sumo-user mailing list
[email protected]<mailto:[email protected]>
To change your delivery options, retrieve your password, or unsubscribe from 
this list, visit
https://dev.eclipse.org/mailman/listinfo/sumo-user


_______________________________________________
sumo-user mailing list
[email protected]<mailto:[email protected]>
To change your delivery options, retrieve your password, or unsubscribe from 
this list, visit
https://dev.eclipse.org/mailman/listinfo/sumo-user


_______________________________________________
sumo-user mailing list
[email protected]<mailto:[email protected]>
To change your delivery options, retrieve your password, or unsubscribe from 
this list, visit
https://dev.eclipse.org/mailman/listinfo/sumo-user

_______________________________________________
sumo-user mailing list
[email protected]
To change your delivery options, retrieve your password, or unsubscribe from 
this list, visit
https://dev.eclipse.org/mailman/listinfo/sumo-user

Reply via email to