Opened 14 years ago

Closed 14 years ago

Last modified 14 years ago

#6144 closed defect (fixed)

[with patch, positive review] Pynac doesn't simplify exp(x)*exp(2*x) to exp(3*x)

Reported by: Mike Hansen Owned by:
Priority: major Milestone: sage-4.0.1
Component: symbolics Keywords:
Cc: William Stein Merged in: 4.0.1.rc2
Authors: Burcin Erocal, Mike Hansen Reviewers: Nick Alexander, Mike Hansen
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

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Description 

sage: exp(x)*exp(2*x)
e^(2*x)*e^x

Attachments (3)

trac_6144-exp_simplify.patch​ (2.2 KB) - added by Burcin Erocal 14 years ago.
trac_6144-pynac_depends.patch​ (1.9 KB) - added by Burcin Erocal 14 years ago.
trac_6144-review.patch​ (609 bytes) - added by Mike Hansen 14 years ago.

Download all attachments as: .zip

Change History (9)

comment:1 Changed 14 years ago by Burcin Erocal

GiNaC doesn't do this either: 

> exp(x)*exp(2*x);
exp(2*x)*exp(x)

I'll try to play with the mul::eval method in pynac to do this. The main problem is doing it without compromising speed.

Cheers,

Burcin

Changed 14 years ago by Burcin Erocal

Attachment: trac_6144-exp_simplify.patch​ added

Changed 14 years ago by Burcin Erocal

Attachment: trac_6144-pynac_depends.patch​ added

comment:2 Changed 14 years ago by Burcin Erocal

Cc: William Stein added
Summary: Pynac doesn't simplify exp(x)*exp(2*x) to exp(3*x) → [with patch, needs review] Pynac doesn't simplify exp(x)*exp(2*x) to exp(3*x)

New pynac package here fixes the exp simplification:

​http://sage.math.washington.edu/home/burcin/pynac/pynac-0.1.8.spkg

Attached patches fix doctests, and change module_list.py to rebuild the sage/symbolic/* modules if the package is updated.

This package also contains a fix for #6163, so these tickets should be merged together.

Changed 14 years ago by Mike Hansen

Attachment: trac_6144-review.patch​ added

comment:3 Changed 14 years ago by Mike Hansen

Burcin's changes look good to me. There was one doctest failure that I fixed and put in trac_6144-review.patch

comment:4 Changed 14 years ago by ncalexan

Summary: [with patch, needs review] Pynac doesn't simplify exp(x)*exp(2*x) to exp(3*x) → [with patch, positive review] Pynac doesn't simplify exp(x)*exp(2*x) to exp(3*x)

All looks good to me! I'm glad this is fixed, I updated the number field tests and was disappointed with the previous behaviour.

comment:5 Changed 14 years ago by Mike Hansen

Resolution: → fixed
Status: new → closed

Merged in 4.0.1.rc2.

comment:6 Changed 14 years ago by Mike Hansen

Authors: → Burcin Erocal, Mike Hansen
Merged in: → 4.0.1.rc2
Reviewers: → Nick Alexander, Mike Hansen
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