29 lines
842 B
Julia
29 lines
842 B
Julia
struct ElementaryMatrix{N,T} <: Groups.GSymbol
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i::Int
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j::Int
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val::T
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ElementaryMatrix{N}(i, j, val=1) where {N} =
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(@assert i ≠ j; new{N,typeof(val)}(i, j, val))
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end
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function Base.show(io::IO, e::ElementaryMatrix)
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print(io, 'E', Groups.subscriptify(e.i), Groups.subscriptify(e.j))
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!isone(e.val) && print(io, "^$(e.val)")
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end
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Base.:(==)(e::ElementaryMatrix{N}, f::ElementaryMatrix{N}) where {N} =
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e.i == f.i && e.j == f.j && e.val == f.val
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Base.hash(e::ElementaryMatrix, h::UInt) =
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hash(typeof(e), hash((e.i, e.j, e.val), h))
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Base.inv(e::ElementaryMatrix{N}) where {N} =
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ElementaryMatrix{N}(e.i, e.j, -e.val)
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function matrix(e::ElementaryMatrix{N,T}) where {N,T}
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m = StaticArrays.MMatrix{N,N,T}(LinearAlgebra.I)
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m[e.i, e.j] = e.val
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x = StaticArrays.SMatrix{N,N}(m)
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return x
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end
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