The Fisher iris data contains four measurements on 150 iris plants (sepal length

Question

The Fisher iris data contains four measurements on 150 iris plants (sepal length, sepal<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

width, petal length, and petal width). Table 3.1 and Table 3.2 show correlations and PCA loadings

for the 50 plants of type Versicolor.

(Recall that the sepals are the usually green parts of the flower that surround the petals.)

Table 3.2 %u2013 PCA Loadings

                   Variance      Cumulative % sepal.length sepal.width petal.length petal.width

Component1 2.93         73.16                 -0.48                    -0.46                    -0.53                  -0.52

Component2 0.55          86.82                 -0.61                     0.67                -0.31                       0.28

Component3 0.39         96.69                   -0.49                -0.54                       0.34                        0.59

(a) Component 1 above can be interpreted as measuring the sum of the four measurements on

the iris plants. Give similar interpretations for Component 2 and Component 3. (4 marks)

(b) When the measurements for the 50 iris plants of type Versicolor are scored using the above

principal components, the scores have the following range of values.

                                 Minimum Score               Maximum Score

Component 1                 %u22122.87                                                3.73

Component 2                 %u22121.59                                                    1.51

Component   3               %u22121.21                                                    1.49

For each of the three principal components, describe the characteristics of an iris plant with

a score near the minimum value, and the characteristics of an iris plant with a score near

the maximum value. (6 marks)

(c) The Fisher iris data contains measurements on three types of iris plants (Setosa, Versicolor,

and Virginica). What graphical technique would you use to decide which of the principal

components best discriminates between the three types of plants? Explain how the

graphical technique would be used. (5 marks)

Explanation / Answer

http://www.mathworks.in/products/demos/statistics/classdemo.html

read this link you will get your answers.Plz rate if it helps.

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