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mirror of https://github.com/kalmarek/PropertyT.jl.git synced 2024-12-24 02:00:30 +01:00

Separation between Groups, FreeGroups and AutGroups

This commit is contained in:
kalmar 2017-01-19 10:14:37 +01:00
parent cec6f98392
commit 1189c38504
3 changed files with 101 additions and 141 deletions

64
AutGroups.jl Normal file
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@ -0,0 +1,64 @@
module AutGroups
using Groups
using Permutations
import Base: inv
export IDSymbol, AutSymbol, AutWord
export rmul_AutSymbol, lmul_AutSymbol, flip_AutSymbol, symmetric_AutSymbol
immutable AutSymbol <: GSymbol
gen::String
pow::Int
ex::Expr
end
IDSymbol(::Type{AutSymbol}) = AutSymbol("(id)", 0, :(IDAutomorphism(N)))
change_pow(s::AutSymbol, n::Int) = reduce(AutSymbol(s.gen, n, s.ex))
function inv(f::AutSymbol)
symbol = f.ex.args[1]
if symbol ==
return change_pow(f, f.pow % 2)
elseif symbol == :σ
perm = invperm(f.ex.args[2])
gen = string('σ', [Char(8320 + i) for i in perm]...)
return AutSymbol(gen, f.pow, :(σ($perm)))
elseif symbol == :(ϱ) || symbol ==
return AutSymbol(f.gen, -f.pow, f.ex)
elseif symbol == :IDAutomorphism
return f
else
throw(ArgumentError("Don't know how to invert $f (of type $symbol)"))
end
end
function rmul_AutSymbol(i,j, pow::Int=1)
gen = string('ϱ',Char(8320+i), Char(8320+j)...)
return AutSymbol(gen, pow, :(ϱ($i,$j)))
end
function lmul_AutSymbol(i,j, pow::Int=1)
gen = string('λ',Char(8320+i), Char(8320+j)...)
return AutSymbol(gen, pow, :(λ($i,$j)))
end
function flip_AutSymbol(j, pow::Int=1)
gen = string('ɛ', Char(8320 + j))
return AutSymbol(gen, pow%2, :(ɛ($j)))
end
function symmetric_AutSymbol(perm::Vector{Int}, pow::Int=1)
perm = Permutation(perm)
ord = order(perm)
pow = pow % ord
perm = perm^pow
gen = string('σ', [Char(8320 + i) for i in array(perm)]...)
return AutSymbol(gen, 1, :(σ($(array(perm)))))
end
typealias AutWord GWord{AutSymbol}
end #end of module AutGroups

25
FreeGroups.jl Normal file
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@ -0,0 +1,25 @@
module FreeGroups
using Groups
import Base: inv, convert
export FGSymbol, IDSymbol
immutable FGSymbol <: GSymbol
gen::String
pow::Int
end
IDSymbol(::Type{FGSymbol}) = FGSymbol("(id)", 0)
FGSymbol(x::String) = FGSymbol(x,1)
inv(s::FGSymbol) = FGSymbol(s.gen, -s.pow)
convert(::Type{FGSymbol}, x::String) = FGSymbol(x)
change_pow(s::FGSymbol, n::Int) = reduce(FGSymbol(s.gen, n))
typealias FGWord GWord{FGSymbol}
FGWord(s::FGSymbol) = FGWord([s])
end #end of module FreeGroups

153
Groups.jl
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@ -1,74 +1,33 @@
module FreeGroups
module Groups
export GSymbol, AutSymbol, Word, GWord, FGWord, AutWord, FGAutomorphism
export GSymbol, GWord
export reduce!, reduce
import Base: length, ==, hash, show
import Base: one, inv, reduce, *, ^
import Base: length, ==, hash, show, convert
import Base: *, ^, convert
import Base: one, inv, reduce, push!, unshift!
abstract GSymbol
immutable FGSymbol <: GSymbol
gen::String
pow::Int
end
immutable AutSymbol <: GSymbol
gen::String
pow::Int
ex::Expr
end
IDSymbol(::Type{FGSymbol}) = FGSymbol("(id)", 0)
IDSymbol(::Type{AutSymbol}) = AutSymbol("(id)", 0, :(IDAutomorphism(N)))
FGSymbol(x::String) = FGSymbol(x,1)
function show(io::IO, s::GSymbol)
if s.pow == 1
print(io, (s.gen))
elseif s.pow == 0
print(io, "(id)")
if s.pow == 0 || s.pow == 1
print(io, s.gen)
else
print(io, (s.gen)*"^$(s.pow)")
end
end
(==)(s::GSymbol, t::GSymbol) = s.gen == t.gen && s.pow == t.pow
length(s::GSymbol) = (s.pow == 0 ? 0 : 1)
one{T<:GSymbol}(::Type{T}) = IDSymbol(T)
one(s::GSymbol) = one(typeof(s))
inv(s::FGSymbol) = FGSymbol(s.gen, -s.pow)
convert(::Type{FGSymbol}, x::String) = FGSymbol(x)
reduce(s::GSymbol) = (s.pow == 0 ? one(s) : s)
change_pow(s::FGSymbol, n::Int) = reduce(FGSymbol(s.gen, n))
change_pow(s::AutSymbol, n::Int) = reduce(AutSymbol(s.gen, n, s.ex))
(^)(s::GSymbol, n::Integer) = change_pow(s, s.pow*n)
function inv(f::AutSymbol)
symbol = f.ex.args[1]
if symbol ==
return FreeGroups.change_pow(f, f.pow % 2)
elseif symbol == :σ
perm = invperm(f.ex.args[2])
gen = string('σ', [Char(8320 + i) for i in perm]...)
return AutSymbol(gen, f.pow, :(σ($perm)))
elseif symbol == :(ϱ) || symbol ==
return AutSymbol(f.gen, -f.pow, f.ex)
elseif symbol == :IDAutomorphism
return f
else
throw(ArgumentError("Don't know how to invert $f (of type $symbol)"))
end
end
function (*){T<:GSymbol}(s::T, t::T)
return GWord{T}([s])*t
end
(*){T<:GSymbol}(s::T, t::T) = return GWord{T}([s])*t
abstract Word
@ -107,11 +66,7 @@ immutable GWord{T<:GSymbol} <: Word
symbols::Vector{T}
end
typealias FGWord GWord{FGSymbol}
typealias AutWord GWord{AutSymbol}
GWord{T<:GSymbol}(s::T) = GWord{T}([s])
FGWord(s::FGSymbol) = FGWord([s])
IDWord{T<:GSymbol}(::Type{T}) = GWord(one(T))
IDWord{T<:GSymbol}(W::GWord{T}) = IDWord(T)
@ -181,12 +136,9 @@ function show(io::IO, W::GWord)
end
end
push!(W::GWord, x) = push!(W.symbols, x...)
unshift!(W::GWord, x) = unshift!(W.symbols, x...)
function r_multiply!(W::GWord, x; reduced::Bool=true)
if length(x) > 0
push!(W, x)
push!(W.symbols, x...)
end
if reduced
reduce!(W)
@ -196,7 +148,7 @@ end
function l_multiply!(W::GWord, x; reduced::Bool=true)
if length(x) > 0
unshift!(W, reverse(x))
unshift!(W.symbols, reverse(x)...)
end
if reduced
reduce!(W)
@ -243,85 +195,4 @@ end
(^)(x::GWord, n::Integer) = power_by_squaring(x,n)
type FGAutomorphism{T<:GSymbol}
domain::Vector{T}
image::Vector{GWord{T}}
map::Function
function FGAutomorphism{T}(domain::Vector{T}, image::Vector{GWord{T}}, map::Function)
length(domain) == length(unique(domain)) ||
throw(ArgumentError("The elements of $domain are not unique"))
length(domain) == length(image) ||
throw(ArgumentError("Dimensions of image and domain must match"))
# Set(vcat([[s.gen for s in reduce!(x).symbols]
# for x in image]...)) == Set(s.gen for s in domain) ||
# throw(ArgumentError("Are You sure that $image defines an automorphism??"))
new(domain, image, map)
end
end
function show(io::IO, X::FGAutomorphism)
title = "Endomorphism of Free Group on $(length(X.domain)) generators, sending"
map = ["$x$y" for (x,y) in zip(X.domain, X.image)]
join(io, vcat(title,map), "\n")
end
(==)(f::FGAutomorphism, g::FGAutomorphism) =
f.domain == g.domain && f.image == g.image
function aut_func_from_table(table::Vector{Tuple{Int,Int}}, GroupIdentity=one(FGWord))
if length(table) == 0
# warn("The map is not an automorphism")
nothing
end
return v->reduce(*,GroupIdentity, v[idx]^power for (idx, power) in table)
end
function aut_func_from_word(domain, w::GWord)
table = Vector{Tuple{Int, Int}}()
for s in w.symbols
pair = (findfirst([x.gen for x in domain], s.gen), s.pow)
push!(table, pair)
end
return aut_func_from_table(table)
end
function FGMap(domain::Vector{FGSymbol}, image::Vector{GWord})
function_vector = Vector{Function}()
for word in image
push!(function_vector, aut_func_from_word(domain, word))
end
return v -> Vector{FGWord}([f(v) for f in function_vector])
end
FGAutomorphism(domain::Vector{FGSymbol}, image::Vector{GWord}) =
FGAutomorphism(domain, image, FGMap(domain, image))
FGAutomorphism(domain::Vector{FGSymbol}, image::Vector{FGSymbol}) =
FGAutomorphism(domain, Vector{GWord}(image))
function FGAutomorphism(domain::Vector, image::Vector)
FGAutomorphism(Vector{FGSymbol}(domain), Vector{GWord}(image))
end
function FGAutomorphism(domain, image)
FGAutomorphism([domain...], [image...])
end
"""Computes the composition g∘f of two morphisms"""
function compose(f::FGAutomorphism, g::FGAutomorphism)
if length(f.image) != length(g.domain)
throw(ArgumentError("Cannot compose $f and $g"))
else
h(v) = g.map(f.map(v))
return FGAutomorphism(f.domain, h(f.domain), h)
end
end
(*)(f::FGAutomorphism, g::FGAutomorphism) = compose(f,g)
end