Issues dealing with BigFloat coefficients
luanborelli opened this issue · 6 comments
I have a system where the coefficients of the polynomials are huge integers. When declaring these polynomials, their coefficients are stored as BigFloat
. When trying to solve the system, the package seems to be unable to handle such coefficients.
solution = solve(F)
F is a System
whose polynomials coefficients have BigFloat
type. Output:
ERROR: MethodError: no method matching HomotopyContinuation.ToricHomotopy(::MixedSystem{Int32, (0x436dfc9bd00f36be, 1)}, ::Vector{Vector{Complex{BigFloat}}})
Closest candidates are:
HomotopyContinuation.ToricHomotopy(::AbstractSystem, ::Vector{Vector{ComplexF64}}) at D:\Users\b46525\.julia\packages\HomotopyContinuation\I1faM\src\homotopies\toric_homotopy.jl:37
HomotopyContinuation.ToricHomotopy(::S, ::Vector{ComplexF64}, ::Vector{Float64}, ::Vector{Float64}, ::StructArrays.StructVector{ComplexF64, NamedTuple{(:re, :im), Tuple{Vector{Float64}, Vector{Float64}}}, Int64}, ::Vector{ComplexF64}, ::Vector{ComplexF64}, ::Vector{ComplexF64}, ::Base.RefValue{ComplexF64}, ::Base.RefValue{ComplexF64}, ::TaylorVector{5, ComplexF64}, ::TaylorVector{4, ComplexF64}, ::TaylorVector{3, ComplexF64}) where S<:AbstractSystem at D:\Users\b46525\.julia\packages\HomotopyContinuation\I1faM\src\homotopies\toric_homotopy.jl:16
Stacktrace:
[1] polyhedral(support::Vector{Matrix{Int32}}, start_coeffs::Vector{Vector{Complex{BigFloat}}}, target_coeffs::Vector{Vector{BigFloat}}; endgame_options::EndgameOptions, tracker_options::TrackerOptions, only_torus::Bool, only_non_zero::Bool, compile::Symbol, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ HomotopyContinuation D:\Users\b46525\.julia\packages\HomotopyContinuation\I1faM\src\polyhedral.jl:320
[2] #polyhedral#226
@ D:\Users\b46525\.julia\packages\HomotopyContinuation\I1faM\src\polyhedral.jl:268 [inlined]
[3] polyhedral(f::System; compile::Symbol, target_parameters::Nothing, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ HomotopyContinuation D:\Users\b46525\.julia\packages\HomotopyContinuation\I1faM\src\polyhedral.jl:201
[4] solver_startsolutions(F::System, starts::Nothing; seed::UInt32, start_system::Symbol, generic_parameters::Nothing, p₁::Nothing, start_parameters::Nothing, p₀::Nothing, target_parameters::Nothing, compile::Symbol, start_subspace::Nothing, target_subspace::Nothing, intrinsic::Nothing, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ HomotopyContinuation D:\Users\b46525\.julia\packages\HomotopyContinuation\I1faM\src\solve.jl:160
[5] solver_startsolutions (repeats 2 times)
@ D:\Users\b46525\.julia\packages\HomotopyContinuation\I1faM\src\solve.jl:115 [inlined]
[6] solve(args::System; show_progress::Bool, threading::Bool, catch_interrupt::Bool, target_parameters::Nothing, stop_early_cb::Function, transform_result::Nothing, transform_parameters::typeof(identity), flatten::Nothing, target_subspaces::Nothing, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
@ HomotopyContinuation D:\Users\b46525\.julia\packages\HomotopyContinuation\I1faM\src\solve.jl:472
[7] solve(args::System)
@ HomotopyContinuation D:\Users\b46525\.julia\packages\HomotopyContinuation\I1faM\src\solve.jl:432
[8] top-level scope
@ Untitled-1:83
Hello
I think I ran into the same issue, I have two very similar systems, but system 1 runs fine, system2 returns the same error as you. At first I thought the error has to do with constant coefficients appearing in the system, but then I generated some random polynomial and that doesn't seem to be the issue.
Maybe it has to do with the differentiate command?
using HomotopyContinuation
using DynamicPolynomials
using Random
# Set random seed
Random.seed!(134)
@polyvar x[1:2]
# Function to generate a random polynomial with BigFloat coefficients
function random_polynomial(variables, degree::Int, num_terms::Int)
polynomial = zero(BigFloat) # Initialize the polynomial with a BigFloat zero
for _ in 1:num_terms
coeff = BigFloat(rand(-10.0:0.1:10.0))
powers = rand(0:degree, length(variables))
monomial = prod(v^p for (v, p) in zip(variables, powers))
polynomial += coeff * monomial
end
return polynomial
end
# Generate two random polynomials of degree 2 with 5 terms each
poly1 = random_polynomial(x, 4, 10)
poly2 = poly1 + BigFloat(1.0) * x[1] + BigFloat(1.0) * x[2]
grad_p1 = differentiate.(poly1, x)
grad_p2 = differentiate.(poly2, x)
# Define the system of equations
system_1 = System(grad_p1)
system_2 = System(grad_p2)
# Solve the system
R1 = HomotopyContinuation.solve(system_1)
println("Result: ", R1)
R2 = HomotopyContinuation.solve(system_2)
println("Result: ", R2)
Hi all,
all I can say is that we never tested against BigFloat
. In principle, everything should be abstractified to an extend that allows any number type. But there is always a chance a bug slipped through. I think, one has to test all functions with BigFloat
input to understasnd what goes wrong.
@gescholt Can you try @var
instead of @polyvar
?
@PBrdng @var
gives the same output:
ERROR: MethodError: no method matching HomotopyContinuation.ToricHomotopy(::MixedSystem{(0xd448607d78e104ed, 1)}, ::Vector{Vector{Complex{BigFloat}}})
Closest candidates are:
HomotopyContinuation.ToricHomotopy(::S, ::Vector{ComplexF64}, ::Vector{Float64}, ::Vector{Float64}, ::StructArrays.StructVector{ComplexF64, @NamedTuple{re::Vector{Float64}, im::Vector{Float64}}, Int64}, ::Vector{ComplexF64}, ::Vector{ComplexF64}, ::Vector{ComplexF64}, ::Base.RefValue{ComplexF64}, ::Base.RefValue{ComplexF64}, ::TaylorVector{5, ComplexF64}, ::TaylorVector{4, ComplexF64}, ::TaylorVector{3, ComplexF64}) where S<:AbstractSystem
@ HomotopyContinuation ~/.julia/packages/HomotopyContinuation/NcbGJ/src/homotopies/toric_homotopy.jl:16
HomotopyContinuation.ToricHomotopy(::AbstractSystem, ::Vector{Vector{ComplexF64}})
@ HomotopyContinuation ~/.julia/packages/HomotopyContinuation/NcbGJ/src/homotopies/toric_homotopy.jl:37
@PBrdng, switching the method to HomotopyContinuation.solve(system_2; start_system=:total_degree)
indeed make the computation work.
@PBrdng, switching the method to
HomotopyContinuation.solve(system_2; start_system=:total_degree)
indeed make the computation work.
Then, the problem is the overflow in the polyhedral homotopy.
It could be, though, that BigFloats
are converted to usual floats in the implementation. Like I said, no one has ever tested this against BigFloats
.
Numerically we will not make use of any of the additional precision provided by big floats. So any fix would just truncate the coefficients .