How to work around unsupported rational coefficients in AbstractAlgebra for polynomial rings in Julia?

General Usage
1

I’m working with the AbstractAlgebra.jl library in Julia and encountered an issue when defining an ideal in a polynomial ring with rational coefficients. Here’s the minimal example:

using AbstractAlgebra

# Integer coefficients (works fine)
R, (x, y) = polynomial_ring(ZZ, [:x, :y]; internal_ordering=:degrevlex)
V = [2x*y, 3x + y]
I = Generic.Ideal(R, V)  # This works

# Rational coefficients (throws an error)
R, (x, y) = polynomial_ring(QQ, [:x, :y]; internal_ordering=:degrevlex)
V = [0.1x*y, 0.1x + y]
# I = Generic.Ideal(R, V)  # Error: rational coefficients are not supported

The issue arises when I use rational coefficients (QQ or 0.1). It seems like Generic.Ideal doesn’t support this type of coefficient.

Question:

  • Is there a known workaround to handle ideals with rational coefficients in AbstractAlgebra.jl?
  • Alternatively, is there another Julia package that supports this functionality for polynomial rings?

Any suggestions or insights would be appreciated. Thanks!

2

0.1 is not a rational coefficient, but a floating point number.

Edit: Use 1//10 instead of 0.1.

1 Like
3

yeah, sorry that example wasn’t qiute right. but the actual code that I need to work w/h has rational coeffs coming from QQ.