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Finding coefficients of complex polynomials [closed]

asked 2022-03-26 00:09:51 +0200

FKalker gravatar image


I've found that the function coefficients() behaves differently when the coefficients of a polynomial are complex instead of real. For example:

sage: R.<x, y> = PolynomialRing(ZZ[I], 2) 
sage: F = 2*I*x*y + 3*x^2*y^3
sage: F.coefficients()
[[2*I*y, 1], [3*y^3, 2]]
sage: G = 2*x*y + 3*x^2*y^3
sage: G.coefficients()
[3, 2]

Also a similar thing happens with univariate polynomials over CC.

sage: S.<z> = PolynomialRing(CC)
sage: f = z^2 + z + I
sage: f.coefficients()
[[1.00000000000000*I, 0], [1.00000000000000, 1], [1.00000000000000, 2]]
sage: g = z^2 + z + 1
sage: g.coefficients()
[1.00000000000000, 1.00000000000000, 1.00000000000000]

Why is there this difference? How can I find a list of the coefficients like when the polynomials are purely real? This is in SageMath version 8.1, is it maybe the issue that this version is outdated?

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Closed for the following reason the question is answered, right answer was accepted by FKalker
close date 2022-03-26 00:22:22.737520

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answered 2022-03-26 00:21:58 +0200

FKalker gravatar image

It is indeed the case that my sagemath version is outdated

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