Merge branch 'master' into cosmetics

This commit is contained in:
kalmar 2017-01-31 16:55:23 +01:00
commit c3ee520521
5 changed files with 201 additions and 18 deletions

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@ -6,12 +6,18 @@ os:
julia:
- release
- nightly
matrix:
fast_finish: true
allow_failures:
julia: nightly
notifications:
email: false
# uncomment the following lines to override the default test script
#script:
# - if [[ -a .git/shallow ]]; then git fetch --unshallow; fi
# - julia -e 'Pkg.clone(pwd()); Pkg.build("Groups"); Pkg.test("Groups"; coverage=true)'
script:
- if [[ -a .git/shallow ]]; then git fetch --unshallow; fi
- julia -e 'Pkg.clone("https://github.com/scheinerman/Permutations.jl.git")'
- julia -e 'Pkg.clone(pwd()); Pkg.build("Groups"); Pkg.test("Groups"; coverage=true)'
after_success:
# push coverage results to Coveralls
- julia -e 'cd(Pkg.dir("Groups")); Pkg.add("Coverage"); using Coverage; Coveralls.submit(Coveralls.process_folder())'

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@ -1,2 +1,3 @@
julia 0.5
Permutations
Combinatorics

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@ -1,7 +1,8 @@
module Groups
import Base: length, ==, hash, show
import Base: length, ==, hash, show, convert
import Base: one, inv, reduce, *, ^
import Base: findfirst, findnext
export GSymbol, GWord
@ -41,6 +42,7 @@ type GWord{T<:GSymbol} <: Word
end
GWord{T<:GSymbol}(s::T) = GWord{T}([s])
convert{T<:GSymbol, W<:Word}(::Type{W}, s::T) = GWord{T}(s)
IDWord{T<:GSymbol}(::Type{T}) = GWord(one(T))
IDWord{T<:GSymbol}(W::GWord{T}) = IDWord(T)
@ -94,7 +96,10 @@ end
freegroup_reduce(W::GWord) = freegroup_reduce!(deepcopy(W))
hash{T}(W::GWord{T}) = (W.modified && freegroup_reduce!(W); W.savedhash)
function hash{T}(W::GWord{T}, h::UInt)
W.modified && freegroup_reduce!(W)
return W.savedhash + h
end
function (==){T}(W::GWord{T}, Z::GWord{T})
W.modified && freegroup_reduce!(W) # reduce clears the flag and recalculate the hash
@ -172,6 +177,72 @@ end
(^)(x::GWord, n::Integer) = power_by_squaring(x,n)
(^){T<:GSymbol}(x::T, n::Integer) = GWord(x)^n
is_subsymbol(s::GSymbol, t::GSymbol) =
s.gen == t.gen && (0 s.pow t.pow || 0 s.pow t.pow)
function findfirst(W::GWord, Z::GWord)
n = length(Z.symbols)
@assert n > 1
for (idx,a) in enumerate(W.symbols)
if idx + n - 1 > length(W.symbols)
break
end
first = is_subsymbol(Z.symbols[1],a)
if first
middle = W.symbols[idx+1:idx+n-2] == Z.symbols[2:end-1]
last = is_subsymbol(Z.symbols[end], W.symbols[idx+n-1])
if middle && last
return idx
end
end
end
return 0
end
function findnext(W::GWord, Z::GWord, i::Integer)
t = findfirst(GWord{eltype(W.symbols)}(W.symbols[i:end]), Z)
if t > 0
return t+i-1
else
return 0
end
end
function replace!(W::GWord, index, toreplace::GWord, replacement::GWord; asserts=true)
n = length(toreplace.symbols)
if asserts
@assert is_subsymbol(toreplace.symbols[1], W.symbols[index])
@assert W.symbols[index+1:index+n-2] == toreplace.symbols[2:end-1]
@assert is_subsymbol(toreplace.symbols[end], W.symbols[index+n-1])
end
first = W.symbols[index]*inv(toreplace.symbols[1])
last = W.symbols[index+n-1]*inv(toreplace.symbols[end])
replacement = first*replacement*last
splice!(W.symbols, index:index+n-1, replacement.symbols)
Groups.freegroup_reduce!(W)
return W
end
function replace(W::GWord, index, toreplace::GWord, replacement::GWord)
replace!(deepcopy(W), index, toreplace, replacement)
end
function replace_all!{T}(W::GWord{T}, subst_dict::Dict{GWord{T}, GWord{T}})
for toreplace in reverse!(sort!(collect(keys(subst_dict)),by=length))
replacement = subst_dict[toreplace]
i = findfirst(W, toreplace)
while i 0
replace!(W,i,toreplace, replacement)
i = findnext(W, toreplace, i)
end
end
return W
end
replace_all(W::GWord, subst_dict::Dict{GWord, GWord}) = replace_all!(deepcopy(W), subst_dict)
include("free_groups.jl")
include("automorphism_groups.jl")

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@ -7,19 +7,31 @@ immutable AutSymbol <: GSymbol
gen::String
pow::Int
ex::Expr
fmap::Function
imap::Function
end
function (f::AutSymbol){T}(v::Vector{GWord{T}})
if f.pow > 0
map = f.fmap
else
map = f.imap
end
for i in 1:abs(f.pow)
v::Vector{GWord{T}} = map(v)
end
return v
end
(==)(s::AutSymbol, t::AutSymbol) = s.gen == t.gen && s.pow == t.pow
hash(s::AutSymbol, h::UInt) = hash(s.gen, hash(s.pow, hash(:AutSymbol, h)))
IdSymbol(::Type{AutSymbol}) = AutSymbol("(id)", 0, :(IdAutomorphism(N)))
IdSymbol(::Type{AutSymbol}) = AutSymbol("(id)", 0, :(Id(N)), v -> Vector{GWord}(v), v -> Vector{GWord}(v))
function change_pow(s::AutSymbol, n::Int)
if n == 0
return one(s)
end
symbol = s.ex.args[1]
if symbol ==
return flip_AutSymbol(s.ex.args[2], pow=n)
@ -29,29 +41,58 @@ function change_pow(s::AutSymbol, n::Int)
return rmul_AutSymbol(s.ex.args[2], s.ex.args[3], pow=n)
elseif symbol ==
return lmul_AutSymbol(s.ex.args[2], s.ex.args[3], pow=n)
elseif symbol == :IdAutomorphism
elseif symbol == :Id
return s
else
warn("Changing an unknown type of symbol! $s")
return AutSymbol(s.gen, n, s.ex)
return AutSymbol(s.gen, n, s.ex, s.fmap, s.imap)
end
end
inv(f::AutSymbol) = change_pow(f, -f.pow)
function ϱ(i,j)
# @assert i ≠ j
return v -> [(k!=i ? GWord(v[k]) : v[i]*v[j]) for k in eachindex(v)]
end
function ϱ_inv(i,j)
# @assert i ≠ j
return v -> [(k!=i ? GWord(v[k]) : v[i]*v[j]^-1) for k in eachindex(v)]
end
function λ(i,j)
# @assert i ≠ j
return v -> ([(k!=i ? GWord(v[k]) : v[j]*v[i]) for k in eachindex(v)])
end
function λ_inv(i,j)
# @assert i ≠ j
return v -> ([(k!=i ? GWord(v[k]) : v[j]^-1*v[i]) for k in eachindex(v)])
end
ɛ(i) = v -> [(k!=i ? GWord(v[k]) : v[k]^-1) for k in eachindex(v)]
function σ(perm)
# @assert sort(perm) == collect(1:length(perm))
return v -> [GWord(v[perm[k]]) for k in eachindex(v)]
end
function rmul_AutSymbol(i,j; pow::Int=1)
gen = string('ϱ',Char(8320+i), Char(8320+j)...)
return AutSymbol(gen, pow, :(ϱ($i,$j)))
return AutSymbol(gen, pow, :(ϱ($i,$j)), ϱ(i,j), ϱ_inv(i,j))
end
function lmul_AutSymbol(i,j; pow::Int=1)
gen = string('λ',Char(8320+i), Char(8320+j)...)
return AutSymbol(gen, pow, :(λ($i,$j)))
return AutSymbol(gen, pow, :(λ($i,$j)), λ(i,j), λ_inv(i,j))
end
function flip_AutSymbol(j; pow::Int=1)
gen = string('ɛ', Char(8320 + j))
return AutSymbol(gen, (2+ pow%2)%2, :(ɛ($j)))
return AutSymbol(gen, (2+ pow%2)%2, :(ɛ($j)), ɛ(j), ɛ(j))
end
function symmetric_AutSymbol(perm::Vector{Int}; pow::Int=1)
@ -59,11 +100,12 @@ function symmetric_AutSymbol(perm::Vector{Int}; pow::Int=1)
ord = order(perm)
pow = pow % ord
perm = perm^pow
if array(perm) == collect(1:length(perm))
p = array(perm)
if p == collect(1:length(p))
return one(AutSymbol)
else
gen = string('σ', [Char(8320 + i) for i in array(perm)]...)
return AutSymbol(gen, 1, :(σ($(array(perm)))))
gen = string('σ', [Char(8320 + i) for i in p]...)
return AutSymbol(gen, 1, :(σ($p)), σ(p), σ(array(inv(perm))))
end
end
@ -77,6 +119,13 @@ end
typealias AutWord GWord{AutSymbol}
function (F::AutWord)(v)
for f in F.symbols
v = f(v)
end
return v
end
convert(::Type{AutWord}, s::AutSymbol) = GWord(s)
function simplify_perms!(W::AutWord)
@ -100,5 +149,6 @@ function simplify_perms!(W::AutWord)
end
end
end
deleteat!(W.symbols, find(x -> x.pow == 0, W.symbols))
return reduced
end

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@ -40,9 +40,15 @@ end
@test isa(Groups.GWord(s), Groups.GWord)
@test isa(Groups.GWord(s), FGWord)
@test isa(FGWord(s), Groups.GWord)
@test isa(convert(FGWord, s), GWord)
@test isa(convert(FGWord, s), FGWord)
@test isa(Vector{FGWord}([s,t]), Vector{FGWord})
@test Vector{GWord{FGSymbol}}([s,t]) == Vector{FGWord}([s,t])
@test isa(s*s, FGWord)
@test s*s == s^2
@test t*s s*t
@test Vector{GWord}([s,t]) == [s^2*s^-1, t]
@test hash([t^1,s^1]) == hash([t^2*inv(t),s*inv(s)*s])
end
@testset "eltary functions" begin
@test length(FGWord(s)) == 1
@ -56,6 +62,7 @@ end
@test isa(one(w), FGWord)
@test inv(s*t) == t^-1*s^-1
@test inv(w) == s*t^-1*s^-1
end
@testset "reductions" begin
@ -80,11 +87,33 @@ end
@test (t*s*t^-1)^10 == t*s^10*t^-1
@test (t*s*t^-1)^-10 == t*s^-10*t^-1
end
@testset "replacements" begin
@test Groups.is_subsymbol(s, Groups.change_pow(s,2)) == true
@test Groups.is_subsymbol(s, Groups.change_pow(s,-2)) == false
@test Groups.is_subsymbol(t, Groups.change_pow(s,-2)) == false
@test Groups.is_subsymbol(inv(t), Groups.change_pow(t,-2)) == true
c = s*t*s^-1*t^-1
@test findfirst(c, s^-1*t^-1) == 3
@test findnext(c*s^-1, s^-1*t^-1,3) == 3
@test findnext(c*s^-1*t^-1, s^-1*t^-1,4) == 5
@test findfirst(c*t, c) == 0
w = s*t*s^-1
subst = Dict{FGWord, FGWord}(w => s^1, s*t^-1 => t^4)
@test Groups.replace(c, 1, s*t, one(FGWord)) == s^-1*t^-1
@test Groups.replace(c, 1, w, subst[w]) == s*t^-1
@test Groups.replace(s*c*t^-1, 1, w, subst[w]) == s^2*t^-2
@test Groups.replace(t*c*t, 2, w, subst[w]) == t*s
@test Groups.replace_all!(s*c*s*c*s, subst) == s*t^4*s*t^4*s
end
end
@testset "Automorphisms" begin
@testset "AutSymbol" begin
@test_throws MethodError AutSymbol("a")
@test_throws MethodError AutSymbol("a", 1)
f = AutSymbol("a", 1, :(a(0)))
f = AutSymbol("a", 1, :(a(0)), v -> v, v -> v)
@test isa(f, GSymbol)
@test isa(f, AutSymbol)
@test isa(symmetric_AutSymbol([1,2,3,4]), AutSymbol)
@ -94,7 +123,7 @@ end
end
@testset "AutWords" begin
f = AutSymbol("a", 1, :(a(0)))
f = AutSymbol("a", 1, :(a(0)), v -> v, v -> v)
@test isa(GWord(f), GWord)
@test isa(GWord(f), AutWord)
@test isa(AutWord(f), AutWord)
@ -120,4 +149,30 @@ end
@test a*b == b*a
@test a^3 * b^3 == one(a)
end
@testset "specific Aut(𝔽₄) tests" begin
N = 4
import Combinatorics.nthperm
SymmetricGroup(n) = [nthperm(collect(1:n), k) for k in 1:factorial(n)]
indexing = [[i,j] for i in 1:N for j in 1:N if i≠j]
σs = [symmetric_AutSymbol(perm) for perm in SymmetricGroup(N)[2:end]];
ϱs = [rmul_AutSymbol(i,j) for (i,j) in indexing]
λs = [lmul_AutSymbol(i,j) for (i,j) in indexing]
ɛs = [flip_AutSymbol(i) for i in 1:N];
S = vcat(ϱs, λs, σs, ɛs)
S = vcat(S, [inv(s) for s in S])
@test isa(S, Vector{AutSymbol})
@test length(S) == 102
@test length(unique(S)) == 75
S₁ = [GWord(s) for s in unique(S)]
@test isa(S₁, Vector{AutWord})
p = prod(S₁)
@test length(p) == 75
@test Groups.simplify_perms!(p) == false
@test length(p) == 53
@test Groups.join_free_symbols!(p) == true
end
end