[sage-support] simple integration with absolute value
Good morning, the command integrate( abs(x^2-1), x, -2,2) does not do the job automatically. I have seen on this discussion group another, at least, similar message. Is there an organized list of functions that are yet implemented for integration? How can one cooperate without being a sage programmer? Thank you. Pedro -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
Re: [sage-support] simple integration with absolute value
On Mon, Jul 11, 2011 at 10:30 AM, Pedro Cruz pedrocruzave...@gmail.com wrote: Good morning, the command integrate( abs(x^2-1), x, -2,2) does not do the job automatically. I have seen on this discussion group another, at least, similar message. Is there an organized list of functions that are yet implemented for integration? Sage's symbolic integration is currently just calling out to Maxima, so you might ask about this on a Maxima list. Maxima's symbolic integration is some huge undocumented lisp program from ages gone by... The above doesn't return a closed result partly because Maxima doesn't: wstein@sage:~$ sage -maxima Maxima 5.23.2 http://maxima.sourceforge.net (%i1) integrate(abs(x^2-1),x,-2,2) ; 2 / [! 2! (%o1) I!x - 1! dx ] / - 2 You might find this useful though: sage: numerical_integral(abs(x^2-1),-2,2) (3.9996, 4.4408920985006262e-14) or sage: N(integral(abs(x^2-1),(x,-2,2))) 3.9996 How can one cooperate without being a sage programmer? Thank you. Pedro -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org -- William Stein Professor of Mathematics University of Washington http://wstein.org -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
Re: [sage-support] dirac delta function
On Mon, Jul 11, 2011 at 9:43 AM, robin hankin hankin.ro...@gmail.comwrote: Hi. When I type integrate(dirac_delta(x),x,-1,1) I expected to get 1, as the documentation clearly implies. But instead I get a symbolic answer. How do I make sage return 1? cheers Robin -- Robin Hankin Uncertainty Analyst hankin.ro...@gmail.com -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org You can use sympy as - import sympy sympy.integrate(sympy.DiracDelta(x), (x,-1,1)) 1 Rajeev -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Maybe not a sage problem?
Hi all, I'm using sage 4.7 on ubuntu 11.04, and I am having problems with 3dplots, but this happens only with the notebook interface. 2D plots are o.k. in both modes, and 3d plots from the terminal work fine, so jmol is there. Whe trying to do a 3d plot, a black square appears in my browser. In previous versions on ubuntu i already had the same problem, howver at that time, things went fine if I used chromium as default browser. Now this solution does not work anymore. I have both OpenJDK and sun-java installed. I think the problem may come form java, since, for instance some geogebra applets do not work properly in my browser. What do I do to know? Thanks JC -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Generating extension fields
Suppose that I have field (it's actually a finite field, but it would be nice to know if this works in more generality) F, and an extension field K. If a[0], ..., a[k] are elements of K, I'd like to generate the field F obtained by adjoining these elements to F as a sage object. Is there a method to do this? Victor -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] integrate() problem
Hi. What's going on here? sage y=(x^2)*exp(x)/(1+exp(x))^2 integrate(y,(x,-infinity,infinity)) 0 /sage Sage gives me zero here. But 'y' is strictly positive everywhere, and I happen to know that the analytic answer is pi^2/3. What's going on here? -- Robin Hankin Uncertainty Analyst hankin.ro...@gmail.com -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
[sage-support] Socket.error
Hi, Using Windows 7, Virtualbox, Sage 4.7 I got the following message: socket.error Last listings: 429 os.chdir(cwd) 430 if e == 256: 431raise socket.error What to do? Roland -- To post to this group, send email to sage-support@googlegroups.com To unsubscribe from this group, send email to sage-support+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
