Macaulay2 / Macaulay2/M2

cone for a ComplexMap of nonzero degree

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package issue
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Macaulay2
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Merged PRs (30d)
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Description

There's a comment above `cone(ComplexMap)` saying:
https://github.com/Macaulay2/M2/blob/b1b46da3411804b7b0e3ac07bfa8b7357d242421/M2/Macaulay2/packages/Complexes/ChainComplexMap.m2#L857-L860
@ggsmith @mikestillman I went back and forth between whether this is what I need or not, and I think it is actually what I need. In particular, taking cone of a map f of nonzero degree isn't the same as cone of `map(target f, (source f)[-degree f], i -> f_(i-degree f))`, is it?

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Research direction

Start with the comment above cone(ComplexMap) in M2/Macaulay2/packages/Complexes/ChainComplexMap.m2 around lines 857-860. Compare the documented behavior with cones of maps having nonzero degree and determine the intended semantics before identifying the needed change and corresponding regression coverage.

Written by the indexing model from the issue text.

Assessment

Domain
tooling
Issue type
Feature
Difficulty
5/5
Estimated time
Over a week
Activity status
Quiet
Clarity
Needs clarification
Newbie friendliness
30/100

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