homogenization for ideal with ZZ^m grading (oscar-system#2372)

* homogenization for ideal with ZZ^m grading * Minor improvements; better comments * 20230630 faster ideal homogenization * Fixed 3 edge cases: 0 ideal, std graded, general ZZ^1 grading * Revised default pos for homogenizaing vars * Renamed: old impl is now homogenization_via_saturation; new is just homogenization * Improved homog (now for all gradings) * Avoid comouting GB in _gens_for_homog_via_sat * Removed some debug print stmts * Revised IO for homogenization (see discussion 2582) * Revised to new syntax/UI for specifying position * Further cleaning & tidying * Updated call to homogenization to new syntax * Updated method signatures for homogenization
JohnAAbbott · Jul 27, 2023 · 1deabec · 1deabec
1 parent c9b9a80
commit 1deabec
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diff --git a/docs/src/CommutativeAlgebra/ideals.md b/docs/src/CommutativeAlgebra/ideals.md
@@ -248,11 +248,11 @@ equidimensional_hull_radical(I::MPolyIdeal)
 Referring to [KR05](@cite) for definitions and technical details, we discuss homogenization and dehomogenization in the context of $\mathbb Z^m$-gradings. 
 
 ```@docs
-homogenization(f::MPolyRingElem, W::Union{ZZMatrix, Matrix{<:IntegerUnion}}, var::VarName, pos::Int = 1)
+homogenization(f::MPolyRingElem, W::Union{ZZMatrix, Matrix{<:IntegerUnion}}, var::VarName; pos::Union{Int,Nothing}=nothing)
 ```
 
 ```@docs
-homogenization(f::MPolyRingElem, var::VarName, pos::Int=1)
+homogenization(f::MPolyRingElem, var::VarName; pos::Union{Int,Nothing}=nothing)
 ```
 
 ```@docs

diff --git a/experimental/PlaneCurve/src/AffinePlaneCurve.jl b/experimental/PlaneCurve/src/AffinePlaneCurve.jl
@@ -522,7 +522,7 @@ function arithmetic_genus(C::AffinePlaneCurve)
    K = base_ring(parent(F))
    R, (x, y, z) = polynomial_ring(K, ["x", "y", "z"])
    T, _ = grade(R)
-   G = homogenization(F, T, 3)
+   G = homogenization(F, T; pos=3)
    D = ProjPlaneCurve(G)
    return arithmetic_genus(D)
 end
@@ -551,7 +551,7 @@ function geometric_genus(C::AffinePlaneCurve)
    K = base_ring(parent(F))
    R, (x, y, z) = polynomial_ring(K, ["x", "y", "z"])
    T, _ = grade(R)
-   G = homogenization(F, T, 3)
+   G = homogenization(F, T; pos=3)
    D = ProjPlaneCurve(G)
    return geometric_genus(D)
 end