'data.frame': 840 obs. of 9 variables:
$ individual: Factor w/ 210 levels "1","2","3","4",..: 1 1 1 1 2 2 2 2 3 3 ...
$ mode : Factor w/ 4 levels "air","train",..: 1 2 3 4 1 2 3 4 1 2 ...
$ choice : Factor w/ 2 levels "no","yes": 1 1 1 2 1 1 1 2 1 1 ...
$ wait : int 69 34 35 0 64 44 53 0 69 34 ...
$ vcost : int 59 31 25 10 58 31 25 11 115 98 ...
$ travel : int 100 372 417 180 68 354 399 255 125 892 ...
$ gcost : int 70 71 70 30 68 84 85 50 129 195 ...
$ income : int 35 35 35 35 30 30 30 30 40 40 ...
$ size : int 1 1 1 1 2 2 2 2 1 1 ...