comboCount

permuteCount

Source vector. If <code>v</code> is a positive integer, it will be converted to the sequence <code>1:v</code>. If <code>v</code> is a negative integer, it will be converted to the sequence <code>v:-1</code>. All atomic types are supported (See <code><a rd-options="" href="/link/is.atomic?package=RcppAlgos&version=2.5.0" data-mini-rdoc="RcppAlgos::is.atomic">is.atomic</a></code>).

Number of elements to choose. If <code>repetition = TRUE</code> or <code>freqs</code> is utilized, <code>m</code> can exceed the length of <code>v</code>. If <code>m = NULL</code>, the length will default to <code>length(v)</code> or <code>sum(freqs)</code>.

Logical value indicating whether combinations/permutations should be with or without repetition. The default is <code>FALSE</code>.

repetition

A vector of frequencies used for producing all combinations/permutations of a multiset of <code>v</code>. Each element of <code>freqs</code> represents how many times each element of the source vector, <code>v</code>, is repeated. It is analogous to the <code>times</code> argument in <code><a rd-options="base" href="/link/rep?package=RcppAlgos&version=2.5.0&to=base" data-mini-rdoc="base::rep">rep</a></code>. The default value is <code>NULL</code>.

freqs

Calculate the number of combinations/permutations of a vector chosen \(m\) at a time with or without replacement. Additionally, these functions can calculate the number of combinations/permutations of multisets.

Combinations

permutations

combinatorics

Provides optimized functions and flexible combinatorial iterators
implemented in C++ for solving problems in combinatorics and
computational mathematics. Utilizes the RMatrix class from 'RcppParallel'
for thread safety. There are combination/permutation functions with
constraint parameters that allow for generation of all results of a vector
meeting specific criteria (e.g. generating integer partitions
or finding all combinations such that the sum is between two bounds).
Capable of generating specific combinations/permutations (e.g. retrieve
only the nth lexicographical result) which sets up nicely for
parallelization as well as random sampling. Gmp support permits exploration
where the total number of results is large (e.g. comboSample(10000, 500,
n = 4)). Additionally, there are several high performance number theoretic
functions that are useful for problems common in computational mathematics.
Some of these functions make use of the fast integer division library
'libdivide'. The primeSieve function is based on the segmented sieve of
Eratosthenes implementation by Kim Walisch. It is also efficient for large
numbers by using the cache friendly improvements originally developed by
Tom<c3><a1>s Oliveira. Finally, there is a prime counting function that implements
Legendre's formula based on the work of Kim Walisch.

Joseph Wood

RcppAlgos

High Performance Tools for Combinatorics and Computational
Mathematics

comboCount function

Source vector. If <code>v</code> is a positive integer, it will be converted to the sequence <code>1:v</code>. If <code>v</code> is a negative integer, it will be converted to the sequence <code>v:-1</code>. All atomic types are supported (See <code><a rd-options='' href='is.atomic'>is.atomic</a></code>).

A vector of frequencies used for producing all combinations/permutations of a multiset of <code>v</code>. Each element of <code>freqs</code> represents how many times each element of the source vector, <code>v</code>, is repeated. It is analogous to the <code>times</code> argument in <code><a rd-options='base' href='rep'>rep</a></code>. The default value is <code>NULL</code>.

comboCount: Number of combinations/permutations

Description

Usage

Arguments

Value

See Also

Examples