Partitions-class

$,Partitions-method

The <code>Partitions</code> class is an S4-class that exposes C++ classes that provide access to iterators and other useful methods.

classes

partitions

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

Partitions-class function

<dl class="dl-horizontal">
 <dt><code>nextIter</code></dt><dd>Retrieve the next lexicographical result</dd>
 <dt><code>nextNIter</code></dt><dd>Pass an integer n to retrieve the next n lexicographical results</dd>
 <dt><code>nextRemaining</code></dt><dd>Retrieve all remaining lexicographical results</dd>
 <dt><code>currIter</code></dt><dd>Returns the current iteration</dd>
 <dt><code>startOver</code></dt><dd>Resets the iterator</dd>
 <dt><code>sourceVector</code></dt><dd>View the source vector</dd>
 <dt><code>summary</code></dt><dd>Returns a list of summary information about the iterator</dd>
 <dt><code>front</code></dt><dd>Retrieve the first lexicographical result</dd>
 <dt><code>back</code></dt><dd>Retrieve the last lexicographical result</dd>
 <dt><code>randomAccess</code></dt><dd>Random access method. Pass a single value or a vector of valid indices. If a single value is passed, the internal index of the iterator will be updated, however if a vector is passed the internal state will not change. GMP support allows for flexible indexing.</dd>
 </dl>

Slots

S4-class for Exposing C++ Partitions Class — Partitions-class

<dl class='dl-horizontal'>
 <dt><code>nextIter</code></dt><dd>Retrieve the next lexicographical result</dd>
 <dt><code>nextNIter</code></dt><dd>Pass an integer n to retrieve the next n lexicographical results</dd>
 <dt><code>nextRemaining</code></dt><dd>Retrieve all remaining lexicographical results</dd>
 <dt><code>currIter</code></dt><dd>Returns the current iteration</dd>
 <dt><code>startOver</code></dt><dd>Resets the iterator</dd>
 <dt><code>sourceVector</code></dt><dd>View the source vector</dd>
 <dt><code>summary</code></dt><dd>Returns a list of summary information about the iterator</dd>
 <dt><code>front</code></dt><dd>Retrieve the first lexicographical result</dd>
 <dt><code>back</code></dt><dd>Retrieve the last lexicographical result</dd>
 <dt><code>randomAccess</code></dt><dd>Random access method. Pass a single value or a vector of valid indices. If a single value is passed, the internal index of the iterator will be updated, however if a vector is passed the internal state will not change. GMP support allows for flexible indexing.</dd>
 </dl>

Partitions-class: S4-class for Exposing C++ Partitions Class

Description

Arguments

Slots

See Also

Examples