Error in absolute_coordinates method with native prime fields

[mjrodgers]

We have the absolute_coordinates method to convert a finite field element to a vector over the prime field corresponding to its internal representation. However while this method is defined for all types of finite field elements, it fails when called on an fpFieldElem or an FpFieldElem due to a missing coeff method for these element types.

julia> k = Native.GF(7)
Finite field of characteristic 7

julia> a = (k)(3)
3

julia> absolute_coordinates(a)
ERROR: MethodError: no method matching coeff(::fpFieldElem, ::Int64)

Closest candidates are:
  coeff(::QQPolyRingElem, ::Int64)
   @ Nemo ~/.julia/packages/Nemo/0n54t/src/flint/fmpq_poly.jl:53
  coeff(::DualRootSpaceElem, ::Int64)
   @ Oscar ~/.julia/dev/Oscar/experimental/LieAlgebras/src/RootSystem.jl:627
  coeff(::fpAbsPowerSeriesRingElem, ::Int64)
   @ Nemo ~/.julia/packages/Nemo/0n54t/src/flint/nmod_abs_series.jl:76
  ...

Stacktrace:
 [1] absolute_coordinates(x::fpFieldElem)
   @ Hecke ~/.julia/packages/Hecke/gMNzj/src/Misc/RelFiniteField.jl:518
 [2] top-level scope
   @ REPL[4]:1

[fieker]

On Wed, Jun 19, 2024 at 04:49:23AM -0700, Morgan Rodgers wrote: Can be argued if coeffs should be added or a direct implementation of abs_coord

…

We have the `absolute_coordinates` method to convert a finite field element to a vector over the prime field corresponding to its internal representation. However while this method is defined for all types of finite field elements, it fails when called on an `fpFieldElem` or an `FpFieldElem` due to a missing `coeff` method for these element types. ```julia julia> k = Native.GF(7) Finite field of characteristic 7 julia> a = (k)(3) 3 julia> absolute_coordinates(a) ERROR: MethodError: no method matching coeff(::fpFieldElem, ::Int64) Closest candidates are: coeff(::QQPolyRingElem, ::Int64) @ Nemo ~/.julia/packages/Nemo/0n54t/src/flint/fmpq_poly.jl:53 coeff(::DualRootSpaceElem, ::Int64) @ Oscar ~/.julia/dev/Oscar/experimental/LieAlgebras/src/RootSystem.jl:627 coeff(::fpAbsPowerSeriesRingElem, ::Int64) @ Nemo ~/.julia/packages/Nemo/0n54t/src/flint/nmod_abs_series.jl:76 ... Stacktrace: [1] absolute_coordinates(x::fpFieldElem) @ Hecke ~/.julia/packages/Hecke/gMNzj/src/Misc/RelFiniteField.jl:518 [2] top-level scope @ REPL[4]:1 ``` -- Reply to this email directly or view it on GitHub: #1546 You are receiving this because you are subscribed to this thread. Message ID: ***@***.***>

[mjrodgers]

I went with adding coeffs because it was easy and could possibly fix other issues if anything else generic calls coeffs. But I'm open to the alternative if that's preferable for any reason.