The dataset is in the "data frame" format, an array of data in which each case (here an individual) corresponds to a row, and each variable corresponds to a column. The row labels for these data frames are just row numbers, the column labels are the names of the variables.
The data are taken from "Applied Linear Regression", by Weisberg. The data are originally from a longitudinal study of children in Berkeley, CA. The quantitative variables are:
read.table("http://www.reed.edu/~jones/141/Berkeley.dat",header=T)
"Berkeley" <-
structure(.Data = list(
"wt2" = c(13.6, 12.7, 12.6, 14.8, 12.7, 11.9, 11.5, 13.2, 16.9, 12.7, 11.4,
14.2, 17.2, 13.7, 14.2, 15.9, 14.3, 13.3, 13.8, 11.3, 14.3, 13.4,
12.2, 15.9, 11.5, 14.2, 12.6, 12., 10.9, 12.7, 11.3, 11.8, 15.4,
10.9, 13.2, 14.3, 11.1, 13.6, 13.5, 16.3, 10.2, 12.6, 12.9, 13.3,
13.4, 12.7, 12.2, 15.4, 12.7, 13.2, 12.4, 13.4, 10.6, 12.7, 11.8,
13.3, 13.2, 15.9),
"ht2" = c(90.2,91.4,86.4,87.6,86.7,88.1,82.2,83.8,91.,87.4,84.2,88.4,87.7,
89.6, 91.4, 90., 86.4, 90., 91.4, 81.3, 90.6, 92.2, 87.1, 91.4, 89.7,
92.2, 83.8, 86.2, 85.1, 88.6, 83., 88.9, 89.7, 81.3, 88.7, 88.4, 85.1,
91.4, 86.1, 94., 82.2, 88.2, 87.5, 88.6, 86.9, 86.4, 80.9, 90., 94.,
89.7, 86.4, 86.4, 81.8, 91.4, 88.6, 86.4, 94., 89.2),
"wt9" = c(41.5,31.,30.1,34.1,24.5,29.8,26.,30.1,37.9,27., 25.9, 31.1, 34.6,
34.6, 43.1, 33.2, 30.7, 31.6, 33.4, 29.4, 30.2, 31.1, 27.6, 32.3, 29.,
31.4, 33., 34.2, 28.1, 27.5, 23.9, 32.2, 29.4, 22., 28.8, 38.8, 36.,
31.3, 33.3, 36.2, 23.4, 33.8, 34.5, 34.4, 38.2, 31.7, 26.6, 34.2, 27.7,
28.5, 30.5, 39., 25., 29.8, 27., 41.4, 41.6, 42.4),
"ht9" = c(139.4,144.3,136.5,135.4,128.9,136.,128.5,133.2,145.6,132.4,133.7,
138.3, 134.6, 139., 146., 133.2, 133.3, 130.3, 144.5, 125.4, 135.8,
139.9, 136.8, 140.6, 138.6, 140., 136.5, 137., 129., 139.4, 125.6,
137.1, 133.6, 121.4, 133.6, 134.1, 139.4, 138.1, 138.4, 139.5, 129.8,
144.8, 138.9, 140.3, 143.8, 133.6, 123.5, 139.9, 136.1, 135.8, 131.9,
130.9, 126.3, 135.5, 134., 138.2, 142., 140.8),
"lg9" = c(31.6,26.,26.6,28.2,24.2,26.7,26.5,27.6,29.,26.,25.8,27.3,30.6,
28.9, 32.4, 28.5, 27.3, 27.5, 27., 27.7, 26.7, 27.2, 25.8, 27.9, 24.6,
28.2, 29., 27.3, 27.4, 25.7, 24.5, 28.2, 26.6, 24.4, 26.5, 31.1, 28.2,
27.6, 29.4, 28., 22.6, 28.3, 30.5, 31.2, 29.8, 27.5, 27.2, 29.1, 26.7,
25.5, 28.6, 29.3, 25., 27., 26.5, 32.5, 31., 32.6),
"st9" = c(74.,73.,64.,75.,63.,77.,45.,70.,61.,74.,68.,59.,87.,71., 98.,
82., 73., 68., 92., 70., 70., 63., 73., 69., 61., 74., 57., 44., 48.,
68., 22., 59., 58., 44., 58., 57., 64., 64., 73., 52., 60., 107., 62.,
88., 78., 52., 40., 71., 30., 76., 59., 38., 50., 57., 54., 44., 56.,
74.),
"wt18" = c(110.2,79.4,76.3,74.5,55.7,68.2,78.2,66.5,70.5, 57.3, 50.3, 70.8,
73.7, 75.2, 83.1, 74.3, 72.2, 88.6, 75.9, 64.9, 65.6, 66.4, 59., 68.1,
67.7, 68.5, 71.2, 58.2, 56., 64.5, 53., 52.4, 56.8, 49.2, 55.6, 77.8,
69.6, 56.2, 64.9, 59.3, 49.8, 62.6, 66.6, 65.3, 65.9, 59., 47.4, 60.4,
56.3, 61.7, 52.4, 58.4, 52.8, 67.4, 56.3, 82.8, 68.1, 63.1),
"ht18" = c(179.,195.1,183.7,178.7,171.5,181.8,172.5,174.6,190.4, 173.8, 172.6,
185.2, 178.4, 177.6, 183.5, 178.1, 177., 172.9, 188.4, 169.4, 180.2,
189., 182.4, 185.8, 180.7, 178.7, 169.6, 166.8, 157.1, 181.1, 158.4,
165.6, 166.7, 156.5, 168.1, 165.3, 163.7, 173.7, 169.2, 170.1, 164.2,
176.,170.9,169.2,172.,163.,154.5,172.5, 175.6, 167.2, 164., 161.6,
153.6, 173.5, 166.2, 162.8, 168.6, 169.2),
"lg18" = c(44.1,36.1,36.9,37.3,31.,37.,39.1,37.3,33.9,33.3,31.6,36.6, 39.2,
36.8, 38., 37.8, 36.5, 40.4, 36.5, 35.7, 35.4, 35.3, 33.5, 34.2, 34.3,
37., 38.8, 34.3, 37.8, 34.2, 32.4, 33.8, 32.7, 33.5, 34.1, 39.8, 38.6,
34.2, 36.7, 32.8, 30., 35.8, 38.8, 39., 35.7, 32.7, 32.2, 35.7, 34.,
35.5, 34.8, 33., 33.4, 34.5, 36.2, 42.5, 38.4, 37.9),
"st18" = c(226.,252.,216.,220.,200.,215.,152.,189.,183.,193.,202.,208.,227.,
204., 226., 233., 237., 230., 250., 236., 177., 186., 199., 227., 164.,
219., 107., 130., 101., 149., 112., 136., 118., 110., 104., 138., 108.,
134., 141., 122., 128., 168., 126., 142., 132., 116., 112., 137., 114.,
122., 121., 107., 140., 123., 135., 125., 142., 142.),
"sex" = structure(.Data =
c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2),
levels = c("Male", "Female"), class = "factor")),
names = c("wt2","ht2","wt9","ht9","lg9","st9","wt18","ht18","lg18",
"st18", "sex"),
row.names = as.integer(1:58),
class = "data.frame")