formula_abn function

Formula to adjacency matrix

Internal function that produce a square matrix length(name) with $0,1$ depending on f. f have to start with ~ terms are entries of name terms are separated by + term1 | term2 indicates col(term1) row(term2) puts a 1 term1 | term2:term3: ... : is used as a sep . = all terms in name

formula_abn(f, name)

Returns

A square matrix