Sum of aggr() deos not return the expected array of values along the chosen dimension

[Pierre1]

Hello,

I have the following expression that gives me in a bar chart the time span of an activity (train run) as an array of ~0 and 1 over 24H (each 10 minutes) for a selected day. This expression works fine for a single train.

if(
       (
          ([24H]>=min(if((departureTime-1/12)<0, departureTime+1, departureTime))) and
         ([24H]<=max(if((arrivalTime-1/12)<0, arrivalTime+1,arrivalTime)))
       ),1,0.00000001
  )

If I tried to display the sum of the activities for all trains (trainNumber) using and aggr() by trainNumber and then a sum I do not get the expected result but it seems to be a single value.

sum(aggr(
                           if(
                               (
                                 ([24H]>=min(if((departureTime-1/12)<0, departureTime+1, departureTime))) and
                                 ([24H]<=max(if((arrivalTime-1/12)<0, arrivalTime+1,arrivalTime)))
                              ),1,0.00000001
                   ),trainNumber)
        )

Has anybody a clue why the expression does return an array of value along the dimension 24H and how I could get the expected results (a sum over all trainNumber of the chart shown for a single train in attached picture).

Thanks in advance and best regards

Pierre