25 lines
800 B
Julia
25 lines
800 B
Julia
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module Numerical
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using AbstractAlgebra
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using HomotopyContinuation: Variable, Expression, System
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using ..Algebraic
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# --- polynomial conversion ---
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# hat tip Sascha Timme
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# https://github.com/JuliaHomotopyContinuation/HomotopyContinuation.jl/issues/520#issuecomment-1317681521
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function Base.convert(::Type{Expression}, f::MPolyRingElem)
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variables = Variable.(symbols(parent(f)))
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f_data = zip(coefficients(f), exponent_vectors(f))
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sum(cf * prod(variables .^ exp_vec) for (cf, exp_vec) in f_data)
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end
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# create a ModelKit.System from an ideal in a multivariate polynomial ring. the
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# variable ordering is taken from the polynomial ring
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function System(I::Generic.Ideal)
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eqns = Expression.(gens(I))
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variables = Variable.(symbols(base_ring(I)))
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System(eqns, variables = variables)
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end
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end
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