#19991 closed enhancement (fixed)

improve dimension function for subschemes of projective products

Reported by: bhutz Owned by: bhutz
Priority: minor Milestone: sage-7.1
Component: algebraic geometry Keywords:
Cc: Merged in:
Authors: Ben Hutz Reviewers: Grayson Jorgenson
Report Upstream: N/A Work issues:
Branch: 5bb1daf (Commits) Commit: 5bb1daf866787964210dc35a5925cc7a0268199c
Dependencies: Stopgaps:

Description

Currently, the dimension function for subscheme of products of projective spaces computes the dimension via the dimension of the image of the Segre embedding. This has two drawbacks. One, the Segre embedding is for products of two components. Two, this adds computation complexity.

This dimension can be computed without the embedding.

Change History (7)

comment:1 Changed 20 months ago by bhutz

  • Branch set to u/bhutz/ticket/19991

comment:2 Changed 20 months ago by bhutz

  • Authors set to Ben Hutz
  • Commit set to 5ba712bb82b0162648516b008805eaf3430e8140
  • Status changed from new to needs_review

I've also extended Segre embedding to work for more than 2 components. Then for fields where the radical is not implemented, we can still get a dimension, albeit more slowly.


New commits:

5ba712b19991: segre embedding and dimension for multiple projective products

comment:3 Changed 20 months ago by git

  • Commit changed from 5ba712bb82b0162648516b008805eaf3430e8140 to 9bbeb1edb8ef70232cf4c35b9127c97d19891d56

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

9bbeb1e19991: minor correction

comment:4 Changed 20 months ago by gjorgenson

  • Reviewers set to Grayson Jorgenson

Doctests pass and everything seems to be working properly. Just a few really minor things:

In algebraic_scheme:

  • line 2738 - spacing with ' -1', should be ' - 1'
  • line 2759 - spacing around '='
  • line 2774 - make exception message lower case
  • line 2776 - parentheses around k not needed, can change (k) to k

comment:5 Changed 20 months ago by git

  • Commit changed from 9bbeb1edb8ef70232cf4c35b9127c97d19891d56 to 5bb1daf866787964210dc35a5925cc7a0268199c

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

5bb1daf19991: fix minor issues

comment:6 Changed 20 months ago by gjorgenson

  • Status changed from needs_review to positive_review

comment:7 Changed 20 months ago by vbraun

  • Branch changed from u/bhutz/ticket/19991 to 5bb1daf866787964210dc35a5925cc7a0268199c
  • Resolution set to fixed
  • Status changed from positive_review to closed
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