Compares all rows of a numeric matrix or data frame X
with respect to the componentwise order. A row X[i, ] is smaller or
equal to a row X[j, ] in the componentwise order, if X[i, k] <=
X[j, k] for k = 1, ..., ncol(X).
compOrd(X)a numeric matrix or a data frame containing numeric or ordered factor variables with at least two columns.
A list containing
pathsa two-column matrix giving all pairs of indices
(i,j) which satisfy all(X[i, ] <= X[j, ]).
colOrdera matrix of the columnwise orders of X. Used to
compute paths and required for other function calls.
The columns of X are sorted sequentially: First all constraints
based on only the first column X[, 1] are activated (set TRUE),
then constraints are dropped based on the orders of the remaining columns.
This avoids nrow(X)^2 / 2 pairwise comparisons.