apache pig - Pig: Max Value per Bag of Tuples -
so have data following:
grunt> describe aliveevents_patient_id; aliveevents_patient_id: {group: int,aliveevents: {(events::patientid: int,events::eventid: chararray,events::etimestamp: datetime,events::value: float,mortality::patientid: int,mortality::mtimestamp: datetime,mortality::label: int)}}
how able biggest value per group of etimestamp?
essentially i'd following:
patient_id, etimestamp 1, 10 1, 20 2, 30
outputs
patient_id, etimestamp 1, 20 2, 30
according question :
let aliveevents_patient_id contain 2 field {patient_id,etimestamp}
then script :
a = group aliveevents_patient_id patient_id; dump a; (1,{(1,10),(1,20)}) (2,{(2,30)}) b = foreach generate group,max(aliveevents_patient_id.etimestamp); dump b; (1,20) (2,30)
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