multigraded function no longer shows mulitgraded betti after first run

[Juan Lanfranco]

I'm running into an issue where if I run the multigraded function a second time, it returns total betti numbers instead of multigraded betti numbers.

Below is an example:

i1 : n=3;
E=entries(id_(ZZ^n));
R=QQ[x_1..x_n, Degrees => E];
I=ideal(x_1*x_2^2, x_1*x_3^2);
peek multigraded minimalBetti (module I)

o4 : Ideal of R

o5 = MultigradedBettiTally{(0, {1, 0, 2}, 3) => 1}
                           (0, {1, 2, 0}, 3) => 1
                           (1, {1, 2, 2}, 5) => 1

i6 : peek multigraded minimalBetti (module I)

o6 = MultigradedBettiTally{(0, {3}, 3) => 2}
                           (1, {5}, 5) => 1 

[Doug Torrance]

This looks to be a bug with how minimalBetti caches its results.  Would you open an issue on GitHub?  https://github.com/Macaulay2/M2/issues/new

[Mahrud Sayrafi]

I agree with Doug that the easiest fix would be to change caching in minimalBetti, but I think the issue is fundamentally with betti Resolution. Compare:

C = res M

peek betti C

peek betti C.Resolution

I've made a pull request to fix this issue: https://github.com/Macaulay2/M2/pull/3339

Mahrud

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