partitionsRank: Rank Partitions/Compositions

In RcppAlgos: High Performance Tools for Combinatorics and Computational Mathematics

Rank Partitions/Compositions

Description

• Generate the rank (lexicographically) of partitions/compositions. These functions are the complement to partitions/compositionsSample. See the examples below.

• GMP support allows for exploration of partitions/compositions of vectors with many elements.

Usage

partitionsRank(..., v, repetition = FALSE, freqs = NULL, target = NULL)

compositionsRank(..., v, repetition = FALSE, freqs = NULL,
                 target = NULL, weak = FALSE)

Arguments

...	vectors or matrices to be ranked.
v	Source vector. If v is a positive integer, it will be converted to the sequence 1:v. If v is a negative integer, it will be converted to the sequence v:-1. All atomic types are supported (See is.atomic).
repetition	Logical value indicating whether partitions/compositions should be with or without repetition. The default is FALSE.
freqs	A vector of frequencies used for producing all partitions of a multiset of v. Each element of freqs represents how many times each element of the source vector, v, is repeated. It is analogous to the times argument in rep. The default value is NULL.
target	Number to be partitioned. If NULL, max(v) will be used.
weak	(Compositions only) Logical flag indicating whether to allow terms of the sequence to be zero.

Details

These algorithms rely on efficiently ranking the n^{th} lexicographical partition.

Value

A vector of class integer, numeric, or bigz determined by the total number of partitions/compositions

Note

v must be supplied.

Author(s)

Joseph Wood

References

Lexicographical order ranking/unranking

See Also

partitionsSample, compositionsSample

Examples

mySamp = partitionsSample(30, 8, TRUE, n = 5, seed = 10, namedSample = TRUE)
myRank = partitionsRank(mySamp, v = 30, repetition = TRUE)
all.equal(as.integer(rownames(mySamp)), myRank)

RcppAlgos documentation built on Oct. 3, 2023, 1:07 a.m.