TableOfReal: Draw biplot...

TableOfReal: Draw biplot...

A command to draw a biplot for each column in the selected TableOfReal object.

Xmin, Xmax, Ymin, Ymax: determine the drawing boundaries.
Split factor: determines the weighing of the row and column structure (see below).

1. Get the singular value decomposition U D V′ of the table.

2. Calculate weighing factors λ for row and columns

λ_r,1 = σ₁^splitFactor

λ_c,1 = σ₁^{1-splitFactor}

λ_r,2 = σ₂^splitFactor

λ_c,2 = σ₂^{1-splitFactor}

where σ₁ and σ₂ are the first and the second singular values

3. For the rows (i from 1..numberOfRows) form:

xr_i = U_i1 λ_r,1

yr_i = U_i2 λ_r,2

4. For the columns (i from 1..numberOfColumns) form:

xc_i = V_i1 λ_c,1

yc_i = V_i2 λ_c,2

5. Plot the points (xr_i, yr_i) and (xc_i, yc_i) in the same figure with the corresponding row and column labels.