Data are the measurements from two very similar species of flea beetle.
A data frame with 36 observations on the following 4 variables.
specimen identification number
measurement of first joint in micrometers
measurement of second joint in micrometers
a factor with levels
Ramsey, F.L. and Schafer, D.W. (2013). The Statistical Sleuth: A Course in Methods of Data Analysis (3rd ed), Cengage Learning.
Lubischew, A.A. (1962). On the Use of Discriminant Functions in Taxonomy, Biometrics 18: 455–477.