PermutationGroup

A group of permutations. Group axioms are verified during construction.

Sources
permutation_group.hpp
permutation_group.cpp
permutation_group.jl

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Constructor

From Permutations

Creates an PermutationGroup out of a vector of Permutation objects.

C++Julia

PermutationGroup(std::vector<Permutation> const &permutations);

PermutationGroup(permutations::Vector{Permutation})

From matrix

Creates a PermutationGroup out of a matrix whose rows specify the individual permutations. If a raw pointer is handed, the matrix is assumed to be in column-major form.

C++Julia

PermutationGroup(arma::Mat<int64_t> const &matrix);
PermutationGroup(int64_t *ptr, int64_t n_permutations, int64_t nsites);

PermutationGroup(matrix::Matrix{Int64})

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Methods

nsites

Returns the number of sites on which the permutations of the group acts.

C++Julia

int64_t nsites(PermutationGroup const &group);

nsites(group::PermutationGroup)::Int64

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size

Returns the size of the permutation group, i.e. the number permutations.

C++Julia

int64_t size(PermutationGroup const &group);

size(group::PermutationGroup)::Int64

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to_string (operator<<)

Converts the PermutationGroup to a readable string representation.

C++Julia

std::string to_string(PermutationGroup const &group);
std::ostream &operator<<(std::ostream &out, PermutationGroup const &group);

to_string(group::PermutationGroup)::String

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Usage Example

C++Julia

// Define a cyclic group of order 3
Permutation p1 = {0, 1, 2};
Permutation p2 = {1, 2, 0};
Permutation p3 = {2, 0, 1};
auto C3 = PermutationGroup({p1, p2, p3});

XDIAG_SHOW(C3.size());
XDIAG_SHOW(C3.nsites());

# Define a cyclic group of order 3
p1 = Permutation([1, 2, 3])
p2 = Permutation([2, 3, 1])
p3 = Permutation([3, 1, 2])
C3 = PermutationGroup([p1, p2, p3])

@show size(C3)
@show nsites(C3)