Iris Data

The data given in Table 1.1, taken from Fisher (1936), are the measurements of the sepal length and width and petal length and width in centimetres of fifty plants for each of three types of iris; Iris setosa, Iris versicolor and Iris virginica. These data are commonly referred to as the “Fisher Iris Data”. Although the data were collected by Dr. Edgar Anderson, R. A. Fisher published the data on Iris setosa and Iris versicolor to demonstrate the use of discriminant functions. The Iris virginica data are used to extend Fisher’s technique and to test Randolph’s (1934) hypothesis that Iris versicolor is a polyploid hybrid of the two other species which is related to the fact that Iris setosa is a diploid species with 38 chromosomes, Iris virginica a tetraploid and Iris versicolor having 108 chromosomes is a hexaploid.