using GroupRings using Base.Test using Nemo @testset "GroupRings" begin @testset "Constructors: PermutationGroup" begin G = PermutationGroup(3) @test isa(GroupRing(G), Nemo.Ring) @test isa(GroupRing(G), GroupRing) RG = GroupRing(G, initialise=false) @test isdefined(RG, :pm) == false @test isdefined(RG, :basis) == false @test isdefined(RG, :basis_dict) == false @test isa(complete(RG), GroupRing) @test size(RG.pm) == (6,6) @test length(RG.basis) == 6 @test RG.basis_dict == GroupRings.reverse_dict(elements(G)) @test isa(GroupRing(G, collect(elements(G))), GroupRing) S = collect(elements(G)) pm = create_pm(S) @test isa(GroupRing(G, S), GroupRing) @test isa(GroupRing(G, S, pm), GroupRing) A = GroupRing(G, S) B = GroupRing(G, S, pm) @test RG == A @test RG == B end @testset "GroupRing constructors FreeGroup" begin using Groups F = FreeGroup(3) S = gens(F) append!(S, [inv(s) for s in S]) S = unique(S) basis, sizes = Groups.generate_balls(S, F(), radius=4) d = GroupRings.reverse_dict(basis) @test_throws KeyError create_pm(basis) pm = create_pm(basis, d, sizes[2]) @test isa(GroupRing(F, basis, pm), GroupRing) @test isa(GroupRing(F, basis, d, pm), GroupRing) A = GroupRing(F, basis, pm) B = GroupRing(F, basis, d, pm) @test A == B end @testset "GroupRingElems constructors/basic manipulation" begin G = PermutationGroup(3) RG = GroupRing(G, initialise=true) a = rand(6) @test isa(GroupRingElem(a, RG), GroupRingElem) @test isa(RG(a), GroupRingElem) for g in elements(G) @test isa(RG(g), GroupRingElem) end @test_throws String GroupRingElem([1,2,3], RG) @test isa(RG(G([2,3,1])), GroupRingElem) p = G([2,3,1]) a = RG(p) @test length(a) == 1 @test isa(a.coeffs, SparseVector) @test a.coeffs[5] == 1 @test a[5] == 1 @test a[p] == 1 @test string(a) == " + 1*[2, 3, 1]" @test RG([0,0,0,0,1,0]) == a s = G([1,2,3]) @test a[s] == 0 a[s] = 2 @test a.coeffs[1] == 2 @test a[1] == 2 @test a[s] == 2 @test string(a) == " + 2*[1, 2, 3] + 1*[2, 3, 1]" @test length(a) == 2 end @testset "Arithmetic" begin G = PermutationGroup(3) RG = GroupRing(G) a = RG(ones(Int, order(G))) @testset "scalar operators" begin @test isa(-a, GroupRingElem) @test (-a).coeffs == -(a.coeffs) @test isa(2*a, GroupRingElem) @test eltype(2*a) == typeof(2) @test (2*a).coeffs == 2.*(a.coeffs) @test isa(2.0*a, GroupRingElem) @test eltype(2.0*a) == typeof(2.0) @test (2.0*a).coeffs == 2.0.*(a.coeffs) @test isa(a/2, GroupRingElem) @test eltype(a/2) == typeof(1/2) @test (a/2).coeffs == 0.5*(a.coeffs) @test isa(convert(Rational{Int}, a), GroupRingElem) @test eltype(convert(Rational{Int}, a)) == Rational{Int} @test convert(Rational{Int}, a).coeffs == convert(Vector{Rational{Int}}, a.coeffs) b = convert(Rational{Int}, a) @test isa(b//4, GroupRingElem) @test eltype(b//4) == Rational{Int} @test isa(b//big(4), GroupElem) @test eltype(b//(big(4)//1)) == Rational{BigInt} @test isa(a//1, GroupRingElem) @test eltype(a//1) == Rational{Int} @test_throws MethodError (1.0*a)//1 end @testset "Additive structure" begin @test RG(ones(Int, order(G))) == sum(RG(g) for g in elements(G)) a = RG(ones(Int, order(G))) b = sum((-1)^parity(g)*RG(g) for g in elements(G)) @test 1/2*(a+b).coeffs == [1.0, 0.0, 1.0, 0.0, 1.0, 0.0] end @testset "Multiplicative structure" begin for g in elements(G), h in elements(G) a = RG(g) b = RG(h) @test a*b == RG(g*h) @test (a+b)*(a+b) == a*a + a*b + b*a + b*b end for g in elements(G) @test GroupRings.star(RG(g)) == RG(inv(g)) @test (one(RG)-RG(g))*GroupRings.star(one(RG)-RG(g)) == 2*one(RG) - RG(g) - RG(inv(g)) @test GroupRings.augmentation((one(RG)-RG(g))) == 0 end z = sum((one(RG)-RG(g))*GroupRings.star(one(RG)-RG(g)) for g in elements(G)) @test GroupRings.augmentation(z) == 0 @test rationalize(Int, z) == convert(Rational{Int}, z) end end end