search for: defectnum

I have a frame which contains 3 columns: "date" "defectnum" "state" And I want to get the most recent state change for a given defect number. date is POSIXct. I have tried: aggregate(ev$date, by=list(ev$defectnum), max) Which appears to be working except that the dates seem to come back as integers (presumably the internal representatio...

...le to add some value. I have a problem I haven't been able to figure out with aggregation, I mentioned it earlier but didn't state it very clearly. Basically I have many "defect events" and I want to grab the most recent event for each defect number: eg: "date" "defectnum" "state" 2004-12-1 10 create 2004-12-2 11 create 2004-12-4 10 close 2004-12-7 11 fix to: "date" "defectnum" "state" 2004-12-4 10 close 2004-12-7 11 fix Now with aggregate I can get the rows I want but not with the state "attached": ag...