search for: v_a2

Dear r-help, I need to draw some lattice plots and have stuck in strange problems. I have a data frame of 405 rows: > str(dframe) `data.frame': 405 obs. of 4 variables: $ year : num 1990 1990 1990 1990 1990 1990 1990 1990 1990 1990 ... $ month: num 1 2 3 4 5 6 7 8 9 10 ... $ V_A2 : num NA NA NA NA NA ... $ V_A3 : num NA NA NA NA NA ... Variable month changes from 1 to 27 as the data frame includes monthly measurements and some aggregations of them. Variable year varies from 1990 to 2004. Variables V_A2 and V_A3 contain floating point values and several NAs (as sometimes...