search for: toposix

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 representation of POSIXct). When I

...rom: object="TimeDateBase") Function: summary (package base) object="TimeDate" Function: td2tz (package AHLCalendar) x="TimeDate" Function: times (package AHLCalendar) x="TimeDate" Function: tojulian (package AHLCalendar) x="TimeDate" Function: toposix (package AHLCalendar) x="TimeDate" Function: tots (package AHLCalendar) x="TimeDate" Function: tzone (package AHLCalendar) x="TimeDate" Function: tzone<- (package AHLCalendar) x="TimeDate" Function: wday (package AHLCalendar) x="TimeDate" Fu...