"""
    iris_data()

Returns a dictionary `D` with the Iris flower data set, discussed in
sections 14.2.1 and 14.3.2.  The items in the dictionary are:
* `D["setosa"]`:  a 50 x 4 matrix with 50 examples of Iris Setosa
* `D["versicolor"]`: a 50 x 4 matrix with 50 examples of Iris Versicolor
* `D["virginica"]`: a 50 x 4 matrix with 50 examples of Iris Virginica.

The columns give values for four features:
1. sepal length in cm
2. sepal width in cm
3. petal length in cm
4. petal width in cm.
"""
function iris_data()

    # 50 examples of Iris Setosa
    setosa = [ 
    5.1 3.5 1.4 0.2; 
    4.9 3.0 1.4 0.2;
    4.7 3.2 1.3 0.2; 
    4.6 3.1 1.5 0.2; 
    5.0 3.6 1.4 0.2; 
    5.4 3.9 1.7 0.4; 
    4.6 3.4 1.4 0.3; 
    5.0 3.4 1.5 0.2;
    4.4 2.9 1.4 0.2; 
    4.9 3.1 1.5 0.1; 
    5.4 3.7 1.5 0.2; 
    4.8 3.4 1.6 0.2; 
    4.8 3.0 1.4 0.1; 
    4.3 3.0 1.1 0.1; 
    5.8 4.0 1.2 0.2; 
    5.7 4.4 1.5 0.4; 
    5.4 3.9 1.3 0.4; 
    5.1 3.5 1.4 0.3;
    5.7 3.8 1.7 0.3; 
    5.1 3.8 1.5 0.3;
    5.4 3.4 1.7 0.2; 
    5.1 3.7 1.5 0.4; 
    4.6 3.6 1.0 0.2; 
    5.1 3.3 1.7 0.5; 
    4.8 3.4 1.9 0.2; 
    5.0 3.0 1.6 0.2; 
    5.0 3.4 1.6 0.4; 
    5.2 3.5 1.5 0.2; 
    5.2 3.4 1.4 0.2; 
    4.7 3.2 1.6 0.2; 
    4.8 3.1 1.6 0.2; 
    5.4 3.4 1.5 0.4; 
    5.2 4.1 1.5 0.1; 
    5.5 4.2 1.4 0.2; 
    4.9 3.1 1.5 0.2;  
    5.0 3.2 1.2 0.2; 
    5.5 3.5 1.3 0.2; 
    4.9 3.6 1.4 0.1; 
    4.4 3.0 1.3 0.2; 
    5.1 3.4 1.5 0.2; 
    5.0 3.5 1.3 0.3; 
    4.5 2.3 1.3 0.3; 
    4.4 3.2 1.3 0.2; 
    5.0 3.5 1.6 0.6; 
    5.1 3.8 1.9 0.4; 
    4.8 3.0 1.4 0.3; 
    5.1 3.8 1.6 0.2; 
    4.6 3.2 1.4 0.2; 
    5.3 3.7 1.5 0.2; 
    5.0 3.3 1.4 0.2 
    ];
    # 50 examples of Iris Versicolor
    versicolor = [ 
    7.0 3.2 4.7 1.4; 
    6.4 3.2 4.5 1.5; 
    6.9 3.1 4.9 1.5; 
    5.5 2.3 4.0 1.3; 
    6.5 2.8 4.6 1.5; 
    5.7 2.8 4.5 1.3; 
    6.3 3.3 4.7 1.6; 
    4.9 2.4 3.3 1.0; 
    6.6 2.9 4.6 1.3; 
    5.2 2.7 3.9 1.4; 
    5.0 2.0 3.5 1.0; 
    5.9 3.0 4.2 1.5; 
    6.0 2.2 4.0 1.0; 
    6.1 2.9 4.7 1.4; 
    5.6 2.9 3.6 1.3; 
    6.7 3.1 4.4 1.4; 
    5.6 3.0 4.5 1.5; 
    5.8 2.7 4.1 1.0; 
    6.2 2.2 4.5 1.5; 
    5.6 2.5 3.9 1.1; 
    5.9 3.2 4.8 1.8; 
    6.1 2.8 4.0 1.3; 
    6.3 2.5 4.9 1.5; 
    6.1 2.8 4.7 1.2; 
    6.4 2.9 4.3 1.3; 
    6.6 3.0 4.4 1.4; 
    6.8 2.8 4.8 1.4; 
    6.7 3.0 5.0 1.7; 
    6.0 2.9 4.5 1.5; 
    5.7 2.6 3.5 1.0; 
    5.5 2.4 3.8 1.1; 
    5.5 2.4 3.7 1.0; 
    5.8 2.7 3.9 1.2; 
    6.0 2.7 5.1 1.6; 
    5.4 3.0 4.5 1.5; 
    6.0 3.4 4.5 1.6; 
    6.7 3.1 4.7 1.5; 
    6.3 2.3 4.4 1.3; 
    5.6 3.0 4.1 1.3; 
    5.5 2.5 4.0 1.3; 
    5.5 2.6 4.4 1.2; 
    6.1 3.0 4.6 1.4; 
    5.8 2.6 4.0 1.2; 
    5.0 2.3 3.3 1.0; 
    5.6 2.7 4.2 1.3; 
    5.7 3.0 4.2 1.2; 
    5.7 2.9 4.2 1.3; 
    6.2 2.9 4.3 1.3; 
    5.1 2.5 3.0 1.1; 
    5.7 2.8 4.1 1.3 
    ];
    # 50 examples of Iris Virginica
    virginica = [ 
    6.3 3.3 6.0 2.5; 
    5.8 2.7 5.1 1.9; 
    7.1 3.0 5.9 2.1; 
    6.3 2.9 5.6 1.8; 
    6.5 3.0 5.8 2.2; 
    7.6 3.0 6.6 2.1; 
    4.9 2.5 4.5 1.7; 
    7.3 2.9 6.3 1.8; 
    6.7 2.5 5.8 1.8; 
    7.2 3.6 6.1 2.5; 
    6.5 3.2 5.1 2.0; 
    6.4 2.7 5.3 1.9; 
    6.8 3.0 5.5 2.1; 
    5.7 2.5 5.0 2.0; 
    5.8 2.8 5.1 2.4; 
    6.4 3.2 5.3 2.3; 
    6.5 3.0 5.5 1.8; 
    7.7 3.8 6.7 2.2; 
    7.7 2.6 6.9 2.3; 
    6.0 2.2 5.0 1.5; 
    6.9 3.2 5.7 2.3; 
    5.6 2.8 4.9 2.0; 
    7.7 2.8 6.7 2.0; 
    6.3 2.7 4.9 1.8; 
    6.7 3.3 5.7 2.1; 
    7.2 3.2 6.0 1.8; 
    6.2 2.8 4.8 1.8; 
    6.1 3.0 4.9 1.8; 
    6.4 2.8 5.6 2.1; 
    7.2 3.0 5.8 1.6; 
    7.4 2.8 6.1 1.9; 
    7.9 3.8 6.4 2.0; 
    6.4 2.8 5.6 2.2; 
    6.3 2.8 5.1 1.5; 
    6.1 2.6 5.6 1.4; 
    7.7 3.0 6.1 2.3; 
    6.3 3.4 5.6 2.4; 
    6.4 3.1 5.5 1.8; 
    6.0 3.0 4.8 1.8; 
    6.9 3.1 5.4 2.1; 
    6.7 3.1 5.6 2.4; 
    6.9 3.1 5.1 2.3; 
    5.8 2.7 5.1 1.9; 
    6.8 3.2 5.9 2.3; 
    6.7 3.3 5.7 2.5; 
    6.7 3.0 5.2 2.3; 
    6.3 2.5 5.0 1.9; 
    6.5 3.0 5.2 2.0; 
    6.2 3.4 5.4 2.3; 
    5.9 3.0 5.1 1.8 
    ]
    return Dict([ ("setosa", setosa), ("versicolor", versicolor),
	("virginica", virginica) ])
end;


