mod function for DynamicalSystem

[gh-Saher-Amasha]

mod function for Dynamical Systems, the function takes as a parameter a prime p and returns the Dynamical System modulo p

[chapoton]

assumed to be invalid. Otherwise, no self-review is allowed.

[gh-Saher-Amasha]

Replying to chapoton:

assumed to be invalid. Otherwise, no self-review is allowed.

did a commit and changed it from new to needs review however I had a problem with my internet and my commit didn't go through so i changed it from needs review to positive review by mistake sorry about that

[roed]

See my comments on #31464, which I've just marked as depending on this ticket (since the branch there includes the changes in this ticket). Ideally, you'll update this ticket with the suggestions that are relevant to the mod method, then once that's reviewed you can merge the updated version into your branch for #31464.

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New commits:

​00a32f2

mod function for Dynamical Systems, the function takes as a parameter a prime p and returns the Dynamical System modulo p

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​f453ffd

fixed style issues

[mkoeppe]

Setting a new milestone for this ticket based on a cursory review.

[gh-EnderWannabe]

This seems like an extension of the change_ring functionality. We can achieve the same result with change_ring as follows:

sage: R.<t> = GF(5)[] 
sage: I = R.ideal(t + 1)
sage: k = ResidueField(I)
sage: F.<t> = FractionField(R)
sage: P.<x,y> = ProjectiveSpace(F, 1)
sage: f = DynamicalSystem([x^2 + t*y^2, y^2])
sage: f.change_ring(k).change_ring(GF(5))

Is there a specific use case where change_ring isn't sufficient?

[mkoeppe]

Stalled in needs_review or needs_info; likely won't make it into Sage 9.5.