Re: [R] aggregating dates

2005-01-31 Thread Gabor Grothendieck
Paul Sorenson vision-bio.com> writes: : : 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) : : Whic

RE: [R] aggregating dates

2005-01-30 Thread Mulholland, Tom
e of the endeavour. If it matters, find the right answer or convince yourself that this code works. > -Original Message- > From: Paul Sorenson [mailto:[EMAIL PROTECTED] > Sent: Monday, 31 January 2005 1:17 PM > To: r-help@stat.math.ethz.ch > Subject: [R] aggregating dates &g

[R] aggregating dates

2005-01-30 Thread Paul Sorenson
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 ba