Opened 10 years ago
Closed 6 years ago
#10074 closed enhancement (fixed)
special values of lesser hyperbolic functions
Reported by:  kcrisman  Owned by:  burcin 

Priority:  minor  Milestone:  sage6.4 
Component:  symbolics  Keywords:  sech, coth, csch 
Cc:  Merged in:  
Authors:  Ralf Stephan  Reviewers:  Frédéric Chapoton 
Report Upstream:  N/A  Work issues:  
Branch:  e064ff3 (Commits)  Commit:  e064ff3a8cc50f28ccdac848c4eab688875d26e8 
Dependencies:  Stopgaps: 
Description
Even though Maxima can evaluate sech(0)
, Sage does this:
sage: cosh(0) 1 sage: sech(0) sech(0)
It seems reasonable to fix this. Part of this is probably that sech
is not a !GiNaC function.
Change History (14)
comment:1 Changed 9 years ago by
comment:2 Changed 7 years ago by
 Milestone changed from sage5.11 to sage5.12
comment:3 Changed 7 years ago by
 Milestone changed from sage6.1 to sage6.2
comment:4 Changed 7 years ago by
 Milestone changed from sage6.2 to sage6.3
comment:5 Changed 6 years ago by
 Milestone changed from sage6.3 to sage6.4
comment:6 Changed 6 years ago by
 Summary changed from Improve lessused hyperbolic functions to special values of lesser hyperbolic functions
comment:7 Changed 6 years ago by
 Branch set to u/rws/improve_less_used_hyperbolic_functions
comment:8 Changed 6 years ago by
 Commit set to b1833cb5e3f2e204e4ec966e404a42835a82f418
 Status changed from new to needs_review
New commits:
b1833cb  10074: special values of coth, sech, csch

comment:10 Changed 6 years ago by
 Commit changed from b1833cb5e3f2e204e4ec966e404a42835a82f418 to 507dc57324d5cdada41940aa9d61120c0846f95a
Branch pushed to git repo; I updated commit sha1. New commits:
507dc57  10074: cosmetics

comment:11 Changed 6 years ago by
 Status changed from needs_work to needs_review
comment:12 Changed 6 years ago by
 Branch changed from u/rws/improve_less_used_hyperbolic_functions to public/ticket/10074
 Commit changed from 507dc57324d5cdada41940aa9d61120c0846f95a to e064ff3a8cc50f28ccdac848c4eab688875d26e8
 Reviewers set to Frédéric Chapoton
comment:14 Changed 6 years ago by
 Branch changed from public/ticket/10074 to e064ff3a8cc50f28ccdac848c4eab688875d26e8
 Resolution set to fixed
 Status changed from positive_review to closed
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Is there a way of initializing a Ginac / Pynac function using a symbolic expression? It would be nice to be able to initialize
sech
by calling simply:And the result would behave just like defining
sech(z) = 1/cosh(z)
in Sage. Then we'd get (as in sage5.0.beta9):Maybe this is naive...