Skip to content

Maxima missing rectform simplification after integral() #11655

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
sagetrac-jan mannequin opened this issue Aug 6, 2011 · 1 comment
Open

Maxima missing rectform simplification after integral() #11655

sagetrac-jan mannequin opened this issue Aug 6, 2011 · 1 comment

Comments

@sagetrac-jan
Copy link
Mannequin

sagetrac-jan mannequin commented Aug 6, 2011

var('a b c x', domain='real')
A = (sin(a) * x^2+sin(b) *x + sin(c)) * exp(-x^2)
Aint = A.integrate(x,-infinity,infinity)

A.imag() is 0

Aint.imag() is a long expression, which doesn't simplify to 0. This surprising for the user.

A slightly different example, actually a generalization of the one above, just works:

var('a b c x', domain='real')
B = (a * x^2+b *x + c) * exp(-x^2)
Bint = B.integrate(x,-infinity,infinity)

Examples can be found here: http://demo.sagenb.org/home/pub/179

CC: @kcrisman

Component: symbolics

Issue created by migration from https://trac.sagemath.org/ticket/11655

@sagetrac-jan sagetrac-jan mannequin added this to the sage-5.11 milestone Aug 6, 2011
@sagetrac-jan sagetrac-jan mannequin added c: symbolics labels Aug 6, 2011
@sagetrac-jan sagetrac-jan mannequin assigned burcin Aug 6, 2011
@jdemeyer jdemeyer modified the milestones: sage-5.11, sage-5.12 Aug 13, 2013
@sagetrac-vbraun-spam sagetrac-vbraun-spam mannequin modified the milestones: sage-6.1, sage-6.2 Jan 30, 2014
@sagetrac-vbraun-spam sagetrac-vbraun-spam mannequin modified the milestones: sage-6.2, sage-6.3 May 6, 2014
@sagetrac-vbraun-spam sagetrac-vbraun-spam mannequin modified the milestones: sage-6.3, sage-6.4 Aug 10, 2014
@rwst
Copy link
Contributor

rwst commented Jan 31, 2015

comment:6

This seems to be a missing rectform simplification because

sage: Aint.expand().simplify_rectform()
1/2*sqrt(pi)*sin(a) + sqrt(pi)*sin(c)

The bug is then rather that Maxima does it not in all cases.

@rwst rwst changed the title A.integrate() has imaginary part for real A Maxima missing rectform simplification after integral() Jan 31, 2015
@mkoeppe mkoeppe removed this from the sage-6.4 milestone Dec 29, 2022
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Projects
None yet
Development

No branches or pull requests

4 participants