#26427 closed defect (fixed)
add doctest to charpoly method of symbolic matrices
Reported by:  tmonteil  Owned by:  

Priority:  major  Milestone:  sage8.5 
Component:  symbolics  Keywords:  
Cc:  rws  Merged in:  
Authors:  Thierry Monteil  Reviewers:  Frédéric Chapoton 
Report Upstream:  N/A  Work issues:  
Branch:  52e1dc2 (Commits, GitHub, GitLab)  Commit:  52e1dc29b94def1cb6fc39a70ea3c61ecf7fd71e 
Dependencies:  Stopgaps: 
Description
As reported on this ask question, the following gives wrong result on Archlinux. Though this distro is not officially supported, this example shows some unexpected behaviour that might appear elsewhere, hence it makes sense to add it on the Sage doctests.
sage: M = matrix(SR, 7, 7, SR.var('a', 49)) sage: M.charpoly().degree() 7
Change History (10)
comment:1 Changed 3 years ago by
 Branch set to u/tmonteil/add_doctest_to_charpoly_method_of_symbolic_matices
comment:2 Changed 3 years ago by
 Commit set to 9000bf56874c9adfa609f166d3fa307403258724
 Status changed from new to needs_review
 Summary changed from add doctest to charpoly method of symbolic matices to add doctest to charpoly method of symbolic matrices
comment:3 Changed 3 years ago by
 Cc rws added
FTR, the incorrect result was caused by building pynac with giac support.
comment:4 Changed 3 years ago by
should be tagged "long" ?
Warning, slow doctest: M.charpoly().degree() Test ran for 1.53 s
comment:5 Changed 3 years ago by
 Commit changed from 9000bf56874c9adfa609f166d3fa307403258724 to 133215627425ce61b13d0d53278cbb624ccb1fea
Branch pushed to git repo; I updated commit sha1. New commits:
1332156  #26427 : log time doctest

comment:6 Changed 3 years ago by
 Commit changed from 133215627425ce61b13d0d53278cbb624ccb1fea to 52e1dc29b94def1cb6fc39a70ea3c61ecf7fd71e
Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:
52e1dc2  #26427 : long time doctest

comment:7 Changed 3 years ago by
You are right, thanks for noticing, i updated the doctest.
comment:8 Changed 3 years ago by
 Reviewers set to Frédéric Chapoton
 Status changed from needs_review to positive_review
ok
comment:9 Changed 3 years ago by
 Branch changed from u/tmonteil/add_doctest_to_charpoly_method_of_symbolic_matices to 52e1dc29b94def1cb6fc39a70ea3c61ecf7fd71e
 Resolution set to fixed
 Status changed from positive_review to closed
comment:10 Changed 3 years ago by
 Milestone changed from sage8.4 to sage8.5
This should be retargeted for 8.5.
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New commits:
#26427 : add doctest for charpoly of matrices over symbolic ring