Regression examples to illustrate the importance of
plotting data and residuals. Y1, Y2, Y3 go with X; Y4 with X4.
"Anscombe" <-
structure(list(X = c(10, 8, 13, 9, 11, 14, 6, 4, 12, 7, 5), Y1 = c(8.04,
6.95, 7.58, 8.81, 8.33, 9.96, 7.24, 4.26, 10.84, 4.82, 5.68),
Y2 = c(9.14, 8.14, 8.74, 8.77, 9.26, 8.1, 6.13, 3.1, 9.13,
7.26, 4.74), Y3 = c(7.46, 6.77, 12.74, 7.11, 7.81, 8.84,
6.08, 5.39, 8.15, 6.42, 5.73), X4 = c(8, 8, 8, 8, 8, 8, 8,
19, 8, 8, 8), Y4 = c(6.58, 5.76, 7.71, 8.84, 8.47, 7.04,
5.25, 12.5, 5.56, 7.91, 6.89)), .Names = c("X", "Y1", "Y2",
"Y3", "X4", "Y4"), row.names = c("1", "2", "3", "4", "5", "6",
"7", "8", "9", "10", "11"), class = "data.frame")