Symbolic Data

In Chapter 2, we have described the classical data analysis paradigm: a rectangular data matrix $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\thicksim}$}}{X} = {\left( {{x_{kj}}} \right)_{n \times p}}$$ defines the relation between the set Ω = {1,…, n}of n individuals or elementary objects and a series of variables Y₁,…, Y_p, where each variable Y _j assumes one single category from a range y _j such that each cell (k,j) of the data matrix $$\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle\thicksim}$}}{X}$$ contains one single value x_kj only.