lal::generate::rand_planar_arrangements Class Reference

Uniformly random generation of planar arrangements of a labeled rooted tree. More...

#include <rand_planar_arrangements.hpp>

Public Member Functions
	rand_planar_arrangements (const graphs::free_tree &T, uint32_t seed=0) noexcept
	Constructor with a constant reference to a free tree.
	rand_planar_arrangements (const graphs::rooted_tree &T, uint32_t seed=0) noexcept
	Constructor with a constant reference to a rooted tree.
	rand_planar_arrangements (const rand_planar_arrangements &Gen)=default
	Default copy constructor.
	rand_planar_arrangements (rand_planar_arrangements &&Gen)=default
	Default move constructor.
	~rand_planar_arrangements ()=default
	Default destructor.
linear_arrangement	get_arrangement () noexcept
	Make a random planar arrangement of a rooted tree.
linear_arrangement	yield_arrangement () noexcept
	Returns a random planar arrangement.

Private Attributes
graphs::free_tree	m_T_copy
	A copy of a free tree.
const graphs::free_tree &	m_T
	The free tree of which we are making planar arrangements uniformly at random.
std::vector< std::vector< node > >	m_rdata
	The random data for all vertices.
std::mt19937	m_gen
	Random number generator.

Detailed Description

Uniformly random generation of planar arrangements of a labeled rooted tree.

A planar arrangement of a directed rooted tree is one in which the root is not covered by any of the tree's edges and there are no edge crossings.

An example of usage of this class is

// given a rooted tree T
lal::generate::rand_planar_arrgements Gen(T);
for (int i = 0; i < 100; ++i) {
    const lal::linear_arrangement arr = Gen.get_arrangement();
    // ...
}

Equivalently,

// given a rooted tree T
lal::generate::rand_planar_arrangements Gen(T);
for (int i = 0; i < 100; ++i) {
    const linear_arrangement arr = Gen.yield_arrangement();
    // ...
}

Constructor & Destructor Documentation

rand_planar_arrangements() [1/4]

lal::generate::rand_planar_arrangements::rand_planar_arrangements ( const graphs::free_tree & T, uint32_t seed = 0 )

noexcept

Constructor with a constant reference to a free tree.

Parameters

T	Input free tree
seed	The seed used for the random generator. If the seed is 0 then a random seed is generated and used.

Precondition

The object t must be a tree (see lal::graphs::free_tree::is_tree).

rand_planar_arrangements() [2/4]

lal::generate::rand_planar_arrangements::rand_planar_arrangements ( const graphs::rooted_tree & T, uint32_t seed = 0 )

noexcept

Constructor with a constant reference to a rooted tree.

Parameters

T	Input rooted tree.
seed	The seed used for the random generator. If the seed is 0 then a random seed is generated and used.

Precondition

The object t must be a tree (see lal::graphs::free_tree::is_tree).

rand_planar_arrangements() [3/4]

lal::generate::rand_planar_arrangements::rand_planar_arrangements ( const rand_planar_arrangements & Gen )

default

Default copy constructor.

Parameters

Gen	Random planar arrangement generator.

rand_planar_arrangements() [4/4]

lal::generate::rand_planar_arrangements::rand_planar_arrangements ( rand_planar_arrangements && Gen )

default

Default move constructor.

Parameters

Gen	Random planar arrangement generator.

Member Function Documentation

get_arrangement()

linear_arrangement lal::generate::rand_planar_arrangements::get_arrangement ( )

noexcept

Make a random planar arrangement of a rooted tree.

Returns

A planar arrangement chosen uniformly at random chosen amongst all planar arrangements of t.

Member Data Documentation

m_rdata

std::vector<std::vector<node> > lal::generate::rand_planar_arrangements::m_rdata

private

The random data for all vertices.

This is a member of the class to avoid its initialisation at every call to get_arrangement.

m_T_copy

graphs::free_tree lal::generate::rand_planar_arrangements::m_T_copy

private

A copy of a free tree.

Used only when this class is constructed with a rooted tree.

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The documentation for this class was generated from the following file:

• lal/generate/rand_planar_arrangements.hpp