arrangements: ipartitions – R documentation

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ipartitions

Partitions iterator

Description

This function returns a Partitions iterator for iterating partitions of an non-negative integer n into k parts or parts of any sizes. The iterator allows users to fetch the next partition(s) via the getnext() method.

Usage

Partitions

ipartitions(n, k = NULL, distinct = FALSE, descending = FALSE,
  skip = NULL)

Arguments

`n`	an non-negative integer to be partitioned
`k`	number of parts
`distinct`	an logical to restrict distinct values
`descending`	an logical to use reversed lexicographical order
`skip`	the number of partitions skipped

Format

An object of class R6ClassGenerator of length 25.

Details

The Partitions class can be initialized by using the convenient wrapper ipartitions or

Partitions$new(n, k = NULL, descending = FALSE)

getnext(d = 1L, layout = NULL, drop = NULL)
collect(layout = "row")
reset()

d: number of fetched arrangements
layout: if "row", "column" or "list" is specified, the returned value would be a "row-major" matrix, a "column-major" matrix or a list respectively
drop: vectorize a matrix or unlist a list

Examples

ipart <- ipartitions(10)
ipart$getnext()
ipart$getnext(2)
ipart$getnext(layout = "column", drop = FALSE)
# collect remaining partitions
ipart$collect()

library(foreach)
foreach(x = ipartitions(6, 2), .combine=c) %do% {
  prod(x)
}

arrangements

Fast Generators and Iterators for Permutations, Combinations, Integer Partitions and Compositions

v1.1.9

MIT + file LICENSE

Authors

Randy Lai [aut, cre]

Initial release

2020-09-12