The pres function can be used to read the result of the psum function for a single channel which comes from the experiment.
Parameters: pres(channel, psum_result)
|channel||Number||The channel is a number which an experiment is running on.|
|psum_result||Binary||The result which is returned by the psum function.|
The following query draws the total amount of sessions on channel 1:
draw number using pres(1, result) as value from ( using psum(participation) as result from @sessions ) as p