combinatoricsRank: Rank Combinations and Permutations In RcppAlgos: High Performance Tools for Combinatorics and Computational Mathematics

 comboRank R Documentation

Rank Combinations and Permutations

Description

• Generate the rank (lexicographically) of combinations/permutations. These functions are the complement to `comboSample` and `permuteSample`. See the examples below.

• GMP support allows for exploration of combinations/permutations of vectors with many elements.

Usage

``````comboRank(..., v, repetition = FALSE, freqs = NULL)
permuteRank(..., v, repetition = FALSE, freqs = NULL)
``````

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 combinations/permutations should be with or without repetition. The default is `FALSE`. `freqs` A vector of frequencies used for producing all combinations/permutations 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`.

Details

These algorithms rely on efficiently ranking the `n^{th}` lexicographical combination/permutation.

Value

A vector of class `integer`, `numeric`, or `bigz` determined by the total number of combinations/permutations

Note

`v` must be supplied.

Joseph Wood

References

`comboSample`, `permuteSample`
``````mySamp = comboSample(30, 8, TRUE, n = 5, seed = 10, namedSample = TRUE)