Transform a region's parts into a disjoint cover of the union

Subtracts from each part all the parts before it, so the result covers the same set with parts meeting only on boundaries, and a measure can be summed over them without double-counting. Parts meeting only in a lower-dimensional slice are left overlapping (see region_algebra).

Usage

disjoin(x, ...)

Arguments

x

A region.

...

For a union_region, max_cells: the cap on the number of cells each difference may decompose into before giving up. Defaults to the ripr.max_cells option, or 1000L when that is unset.

Value

A region covering the same set, whose parts have disjoint interiors, or an empty_region() if x is empty.

See also

region_algebra

Examples

# The two cells of the K = 3 plurality null overlap where candidate 1 trails
# both others. Peeling them apart leaves that region in one of the two.
plurality <-
  simplex_region(vertices = rbind(c(0.5, 0.5, 0), c(0, 1, 0), c(0, 0, 1))) |
  simplex_region(vertices = rbind(c(0.5, 0, 0.5), c(0, 1, 0), c(0, 0, 1)))
peeled <- disjoin(plurality)
length(parts(peeled))
#> [1] 2
peeled == plurality
#> [1] TRUE