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polynomial_ring cached=false for combinatorics #3856

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polynomial_ring cached=false for combinatorics #3856

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6 changes: 3 additions & 3 deletions src/Combinatorics/Matroids/ChowRings.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -60,9 +60,9 @@ function chow_ring(M::Matroid; ring::Union{MPolyRing,Nothing}=nothing, extended:

@req length(var_names) > 0 "Chow ring is empty"
if graded
ring, vars = graded_polynomial_ring(QQ, var_names, cached=false)
ring, vars = graded_polynomial_ring(QQ, var_names; cached=false)
else
ring, vars = polynomial_ring(QQ, var_names, cached=false)
ring, vars = polynomial_ring(QQ, var_names; cached=false)
end
else
if extended
Expand Down Expand Up @@ -166,7 +166,7 @@ function augmented_chow_ring(M::Matroid)
var_names = vcat(element_var_names, flat_var_names)
s = length(var_names)

ring, vars = polynomial_ring(QQ, var_names)
ring, vars = polynomial_ring(QQ, var_names; cached=false)
element_vars = vars[1:n]
flat_vars = vars[n+1:s]

Expand Down
4 changes: 2 additions & 2 deletions src/Combinatorics/Matroids/matroid_strata_grassmannian.jl
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Expand Up @@ -142,7 +142,7 @@ function make_polynomial_ring(Bs::Vector{Vector{Int}}, B::Vector{Int},
F::AbstractAlgebra.Ring)

MC = bases_matrix_coordinates(Bs, B)
R, x = polynomial_ring(F, :"x"=>MC)
R, x = polynomial_ring(F, :"x"=>MC; cached=false)
xdict = Dict{Vector{Int}, MPolyRingElem}([MC[i] => x[i] for i in 1:length(MC)])
return R, x, xdict
end
Expand Down Expand Up @@ -330,7 +330,7 @@ function realization_polynomial_ring(Bs::Vector{Vector{Int}}, A::Vector{Int},
MC = realization_bases_coordinates(Bs, A)
D = partial_matrix_max_rows(MC)
MR = [x for x in MC if x[1] != D[x[2]]]
R, x = polynomial_ring(F, :"x"=>MR)
R, x = polynomial_ring(F, :"x"=>MR; cached=false)
xdict = Dict{Vector{Int}, MPolyRingElem}(MR[i] => x[i] for i in 1:length(MR))
return R, x, xdict
end
Expand Down
6 changes: 3 additions & 3 deletions src/Combinatorics/Matroids/properties.jl
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Expand Up @@ -897,7 +897,7 @@ x^3 + 4*x^2 + 7*x*y + 3*x + y^4 + 3*y^3 + 6*y^2 + 3*y
```
"""
function tutte_polynomial(M::Matroid)
R, (x, y) = polynomial_ring(ZZ, ["x", "y"])
R, (x, y) = polynomial_ring(ZZ, ["x", "y"]; cached=false)
poly = pm_object(M).TUTTE_POLYNOMIAL
exp = Polymake.monomials_as_matrix(poly)
return R(Vector{Int}(Polymake.coefficients_as_vector(poly)),[[exp[i,1],exp[i,2]] for i in 1:size(exp)[1]])
Expand All @@ -918,7 +918,7 @@ q^3 - 7*q^2 + 14*q - 8
```
"""
function characteristic_polynomial(M::Matroid)
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These functions touched here should all at some point be changed allow passing in the polynomial ring, as discussed here in our dev docs

(To be clear, that's not a request to change this PR)

R, q = polynomial_ring(ZZ, 'q')
R, q = polynomial_ring(ZZ, 'q'; cached=false)
return (-1)^rank(M)*tutte_polynomial(M)(1-q,0)
end

Expand All @@ -936,7 +936,7 @@ q^2 - 6*q + 8
```
"""
function reduced_characteristic_polynomial(M::Matroid)
R, q = polynomial_ring(ZZ, 'q')
R, q = polynomial_ring(ZZ, 'q'; cached=false)
p = characteristic_polynomial(M)
Comment on lines +939 to 940
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Suggested change
R, q = polynomial_ring(ZZ, 'q'; cached=false)
p = characteristic_polynomial(M)
p = characteristic_polynomial(M)
R = parent(p)

c = Vector{Int}(undef,degree(p))
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Huh... that seems risky, couldn't one have examples where an Int would over- or underflow?

s = 0
Expand Down