Figure 4.

The result of factor analysis of 28 features and their division into 3 classes. Each of the 28 features is represented in this plot by a vector, and the direction and length of the vector indicate how each feature depends on the underlying factors (class). The orthogonal nature of the majority of the features, in particular w(16), w(22) to w(25) and w(1), w(2) w(12) as well as w(11), is clearly visible. Individual observations are marked in red. On the right side in the corners the characteristic areas have been enlarged.