Eric Archer wrote: > R-help, > > I'm getting some unexpected behavior with subsetting a data frame > (aircraft flight data) that I can't sort out. > Here is a simplified version of my data frame and problem: > > > flight > FlightID TailNo FlightDate HobbsTime FlightCost Date year > 1 4497 6009K <NA> 2.2 330.0 <NA> NA > 2 4498 6009K <NA> 0.8 120.0 <NA> NA > 3 4499 6009K <NA> 0.9 135.0 <NA> NA > 4 4500 6009K <NA> 1.1 165.0 <NA> NA > 5 4501 6009K <NA> 1.5 225.0 <NA> NA > 2587 7083 9206N 4/8/2009 1.5 103.5 2009-04-08 2009 > 2588 7084 9206N 4/10/2009 1.3 89.7 2009-04-10 2009 > 2589 7085 9206N 4/11/2009 1.9 131.1 2009-04-11 2009 > 2590 7086 9206N 4/12/2009 1.3 89.7 2009-04-12 2009 > 2591 7087 9206N 4/15/2009 1.1 75.9 2009-04-15 2009 > 29793 35208 91630 1/21/2006 1.4 107.8 2006-01-21 2006 > 29794 35209 91630 1/21/2006 0.7 53.9 2006-01-21 2006 > 29795 35210 9725B 1/21/2006 1.4 138.6 2006-01-21 2006 > 29796 35212 91630 1/28/2006 1.0 77.0 2006-01-28 2006 > 29797 35213 91630 1/28/2006 1.6 123.2 2006-01-28 2006 > 29798 35214 3386E 1/5/2006 1.1 86.9 2006-01-05 2006 > > I then try to extract the error years : > > > errors <- flight[flight$year > 2006,] > > errors > FlightID TailNo FlightDate HobbsTime FlightCost Date year > NA NA <NA> <NA> NA NA <NA> NA > NA.1 NA <NA> <NA> NA NA <NA> NA > NA.2 NA <NA> <NA> NA NA <NA> NA > NA.3 NA <NA> <NA> NA NA <NA> NA > NA.4 NA <NA> <NA> NA NA <NA> NA > 2587 7083 9206N 4/8/2009 1.5 103.5 2009-04-08 2009 > 2588 7084 9206N 4/10/2009 1.3 89.7 2009-04-10 2009 > 2589 7085 9206N 4/11/2009 1.9 131.1 2009-04-11 2009 > 2590 7086 9206N 4/12/2009 1.3 89.7 2009-04-12 2009 > 2591 7087 9206N 4/15/2009 1.1 75.9 2009-04-15 2009 > > Would someone please explain to me why the new data frame has all > columns (and row names) replaced with NA where year was NA and how to > avoid this behavior?. > Thanks in advance. > > I am using R v2.2.1 on Windows XP. > > Cheers, > eric
[snip] flight$year > 2006 will return TRUE/FALSE, not row numbers. Try this: errors <- subset(flight, subset = year > 2006) Peter Ehlers ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
