Is f1 nested within f2? — isNested • reformulas

Does every level of f1 occur in conjunction with exactly one level of f2? The function is based on converting a triplet sparse matrix to a compressed column-oriented form in which the nesting can be quickly evaluated.

isNested(f1, f2)

Arguments

f1: factor 1
f2: factor 2

Value

TRUE if factor 1 is nested within factor 2

Examples

if (requireNamespace("lme4")) {
   data("Pastes", package = "lme4")
   with(Pastes, isNested(cask, batch))   ## => FALSE
   with(Pastes, isNested(sample, batch))  ## => TRUE
}
#> Loading required namespace: lme4
#> [1] TRUE