On 2018-10-02, kcrisman wrote:
> Please do. It's likely something related to
> https://trac.sagemath.org/ticket/21440 and
> https://trac.sagemath.org/wiki/symbolics#Integrationtickets where you can
> browse to your heart's content :-) For some reason the wrong branch seems
> to get chosen by
On Monday, October 1, 2018 at 4:55:14 PM UTC-4, Simon King wrote:
>
> Hi!
>
> I get the following with sage-8.4.beta5:
> sage: f(x) = cos(pi*x)
> sage: (f(x)*exp(-I*pi*x)).integral(x)(x=1/2) -
> (f(x)*exp(-I*pi*x)).integral(x)(x=-1/2)
> 1/2
> sage:
> integral(sqrt(1+cos(x)^2),x,0,pi)
> >
> > 0
>
> The bug appears to be tickled by the Maxima package abs_integrate.
> Without abs_integrate, integrate(sqrt(1 + cos(x)^2), x, 0, %pi) just
> returns a noun expression.
>
> > Zero is decidedly not correct. The problem is apparently here:
On 2017-10-26, david.guichard wrote:
> integral(sqrt(1+cos(x)^2),x,0,pi)
>
> 0
The bug appears to be tickled by the Maxima package abs_integrate.
Without abs_integrate, integrate(sqrt(1 + cos(x)^2), x, 0, %pi) just
returns a noun expression.
> Zero is decidedly
Comments and (horrible !) workaround in
Trac#14976http://trac.sagemath.org/ticket/14976
.
HTH,
Emmanuel Charpentier
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The problem seems to lie on Sage's side. In the native version of sage :
Maxima 5.30.0 http://maxima.sourceforge.net
using Lisp GNU Common Lisp (GCL) GCL 2.6.7 (a.k.a. GCL)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function
By the way, the problem *might* be larger than that. In Maxima, one can do :
(%i1) display2d:false;
(%o1) false
(%i2) define(h(x),integrate(f(t),t,g1(x),g2(x)));
defint: lower limit of integration must be real; found g1(x)
-- an error. To debug this try: debugmode(true);
(%i3)
On 2013-07-27, Emmanuel Charpentier emanuel.charpent...@gmail.com wrote:
(%i2) define(h(x),integrate(f(t),t,g1(x),g2(x)));
defint: lower limit of integration must be real; found g1(x)
-- an error. To debug this try: debugmode(true);
Well, a way to make this work is to write define(h(x),
On Thursday, May 17, 2012 1:52:38 AM UTC-4, ketchers wrote:
I don't know how to get sage to understand domain : complex so I tried
with assume and here is what happened. Does it make sense?
Yes, it does. Our assumptions go through Maxima, and apparently assuming a
variable is
https://lh6.googleusercontent.com/-BDfI2b3v4HA/T7SRx5zaqBI/AGo/Q6NEGFw8xQw/s1600/Screenshot+from+2012-05-17+00%3A50%3A25.png
I don't know how to get sage to understand domain : complex so I tried
with assume and here is what happened. Does it make sense?
On Sunday, May 13, 2012
On 2012-05-14, JamesHDavenport j.h.davenp...@bath.ac.uk wrote:
It may be branch cut strangeness, but if so it is very strange. The
integrand is clearly well-behaved, and the integral,
while in terms of the incomplete gamma function, seems to be off the usual
branch cut (negative real axis).
It may be branch cut strangeness, but if so it is very strange. The
integrand is clearly well-behaved, and the integral,
while in terms of the incomplete gamma function, seems to be off the
usual
branch cut (negative real axis).
Try domain:complex before calling integrate; that
On Tuesday, May 15, 2012 2:36:34 AM UTC-4, Keshav Kini wrote:
John H Palmieri jhpalmier...@gmail.com writes:
This works for me:
sage: numerical_integral(x*cos(x^3), 0, 0.5)
(0.1247560409610376, 1.3850702913602309e-15)
Interesting...
sage:
On 2012-05-15, kcrisman kcris...@gmail.com wrote:
(%i3) domain:complex;
(%o3) complex
(%i4) integrate(x*cos(x^3),x,0,1/2);
(%o4)
gamma_incomplete(2/3,%i/8)/6+gamma_incomplete(2/3,-%i/8)/6-gamma(2/3)/3
Hmm. I get a different result. I am using the current Git version.
domain : complex;
On 5/15/12 8:33 PM, Keshav Kini wrote:
And maybe that's why plot3d(), unlike plot(), does
seem to generate the deprecation warning.
Sorry---what plot command doesn't generate a deprecation warning?
Thanks,
Jason
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This is now http://trac.sagemath.org/sage_trac/ticket/12947. We've had
some issues with incomplete gamma functions translating properly in the
past, and/or errors in Maxima, but I didn't have time to either look into
that or whether there was another ticket open for this, apologies if there
On 2012-05-14, kcrisman kcris...@gmail.com wrote:
This is now http://trac.sagemath.org/sage_trac/ticket/12947. We've had
some issues with incomplete gamma functions translating properly in the
past, and/or errors in Maxima, but I didn't have time to either look into
that or whether there
On Sunday, May 13, 2012 8:46:41 PM UTC-7, ketchers wrote:
Sage returns negative value for the integral of a positive function
x*cos(x^3) on (0,0.5), if I use abs(cos(x^3))*x, then it gets it correct?
This works for me:
sage: numerical_integral(x*cos(x^3), 0, 0.5)
It may be branch cut strangeness, but if so it is very strange. The
integrand is clearly well-behaved, and the integral,
while in terms of the incomplete gamma function, seems to be off the usual
branch cut (negative real axis).
On Monday, 14 May 2012 15:35:01 UTC+1, Robert Dodier wrote:
On
On Tuesday, March 27, 2012 4:25:48 PM UTC-4, david.guichard wrote:
I've tried this on my 4.6 sage and on 5.0 beta; the main sagenb.org is
not returning calculations for me. Both 4.6 and 5.0 have the same error.
This double integral calculation is correct:
var(r t)
One can also use scipy (faster) or mpmath (very slow)
sage: import scipy.integrate
sage: scipy.integrate.dblquad(lambda x,y:abs(cos(x+y)),0,pi,lambda x:
0,lambda x:pi)
(6.2831850310568189, 8.0696816340264377e-08)
sage: n(2*pi)
6.28318530717959
sage: from mpmath import *
sage: mp.dps = 50;
It's 2*pi since the integral of abs(cos(x+y)) from x=0 to pi is 2
(independent of y). But here's how you can get Sage to compute a
numerical integral for you:
sage: f = lambda y: numerical_integral( lambda x: abs(cos(x+y)), 0,
pi )[0]
sage: f(0.0001)
1.0001
sage: numerical_integral(
On Feb 7, 12:00 pm, Francois Maltey fmal...@nerim.fr wrote:
Santanu Sarkar a crit :
How one can find integral abs(cos(x+y)) where x varies from 0 to pi
and y varies from 0 to pi in Sage?
You must help Sage (in fact Maxima bellow) for these integrals.
The Maxima add-on package
So... There is no solution?
On Dec 9, 6:03 pm, Sand Wraith omegat...@gmail.com wrote:
Does anyone know is this issue only for newest version? (may be I
should use older version of sage)
On 8 дек, 21:47, David Joyner wdjoy...@gmail.com wrote:
Unfortunately, the piecewise class was written
I'm cc'ing Paul Butler who wrote that method.
Paul, are you following this thread?
On Sun, Dec 13, 2009 at 3:32 PM, Eugene Goldberg omegat...@gmail.com wrote:
So... There is no solution?
On Dec 9, 6:03 pm, Sand Wraith omegat...@gmail.com wrote:
Does anyone know is this issue only for newest
Does anyone know is this issue only for newest version? (may be I
should use older version of sage)
On 8 дек, 21:47, David Joyner wdjoy...@gmail.com wrote:
Unfortunately, the piecewise class was written before the symbolic
expressions class and has not kept pace.
The obvious solution produced
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