Re: [R] subscripting in data frames with NA

2008-06-24 Thread Prof Brian Ripley
On Tue, 24 Jun 2008, Agustin Lobo wrote: Dear list: Given str(b3) 'data.frame': 159 obs. of 6 variables: $ index_pollution : num 8.228 10.513 0.549 0.915 10.416 ... $ position_descrip: chr "2" "2" "2" NA ... $ position_geo: chr "3" "0" "3" "3" ... $ institution : Factor w/ 3

Re: [R] subscripting in data frames with NA

2008-06-24 Thread Peter Dalgaard
Agustin Lobo wrote: > Dear list: > > Given > > str(b3) > 'data.frame':159 obs. of 6 variables: > $ index_pollution : num 8.228 10.513 0.549 0.915 10.416 ... > $ position_descrip: chr "2" "2" "2" NA ... > $ position_geo: chr "3" "0" "3" "3" ... > $ institution : Factor w/ 3 le