greedySetCover {RcppGreedySetCover}

Greedy Set Cover

Description

Fast greedy set cover algorithm.

Usage

greedySetCover(X, data.table = TRUE)

Arguments

X

Two-column data.frame in long format: Column 1 identifies the sets, column 2 the elements.

data.table

If TRUE returns a data.table with keys given by sets and elements. If FALSE returns a data.frame, sorted by sets and elements.

Value

If data.table == TRUE a data.table, keyed by sets and elements. Else a data.frame, sorted by sets and elements. Column names are derived from input.

Examples

# Create some data.
set.seed(333)
X <- data.table::rbindlist(
  lapply(
    seq_len(1e4L),
    function(x) list(element=sample.int(n=1e3L,size=sample.int(50L,1L)))
  ),
  idcol="set"
)
# Elements are integers 1,2,...,1000.

# Run set cover
res <- greedySetCover(X,FALSE)
head(res)

# Check if all elements are covered.
identical(sort(unique(res$element)),sort(unique(X$element)))