[sage-support] Re: Is it possible to disable maxima automated simplification ?
Thanks for your detailed answer ! This clarifies lots of things for me ! On 24 juin, 19:05, William Stein wst...@gmail.com wrote: On Wed, Jun 24, 2009 at 6:47 PM, Nicolasnicolas.fresseng...@gmail.com wrote: Sorry, I thought this was clear. when you type sage: a=x+x+1 sage: a 2*x + 1 If I understood correctly, the simplification of x+x by 2*x is done by maxima in the background. Just to be clear, that is definitely *NOT* the case. It used to be the case before sage-4.0, but is not the case now. Here's how you can check this: teragon:~ wstein$ sage -- | Sage Version 4.0.2, Release Date: 2009-06-18 | | Type notebook() for the GUI, and license() for information. | -- sage: x + x + 1 2*x + 1 sage: Exiting SAGE (CPU time 0m0.08s, Wall time 0m23.29s). You have new mail in /var/mail/wstein teragon:~ wstein$ sage -- | Sage Version 4.0.2, Release Date: 2009-06-18 | | Type notebook() for the GUI, and license() for information. | -- sage: f = integrate(sin(x^2)) sage: Exiting SAGE (CPU time 0m0.16s, Wall time 0m6.97s). Exiting spawned Maxima process. teragon:~ wstein$ Notice that the first time there's no Exiting spawned Maxima process. message. I f x is here much more complicated (or if the expression itself is complicated), the simplification process can become lengthy and even crash maxima. So my question was : is this possible that when I ask a in the second line above, that the answer would be x+x+1 Note that maxima isn't involved. Sorry for the trouble Nicolas On 23 juin, 11:19, William Stein wst...@gmail.com wrote: On Tue, Jun 23, 2009 at 9:40 AM, Nicolasnicolas.fresseng...@gmail.com wrote: I am in the writing of a program that deals with rather lengthy symbolic expressions involving unknown functions and differentiation. When running commands like derivatives, it seems that maxima automatically runs into place to simplify the obtained expressions. (This is consistent with the documentation) In interactive sessions, this is perfectly good, but for my application, it has two major problems : - things are slowed down a lot because maxima tries to simplify long expressions which cannot be much simplified - worse : maxima often crashes which renders the whole program difficult to use My solution would be to disable maxima automated simplification but I cannot figure out if this is possible in sage or how to do it (I am using sage.4.0.1 on Fedora 10) Please provide a much more precise example than what you've given above (which is no examples at all). -- William -- William Stein Associate Professor of Mathematics University of Washingtonhttp://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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Is it possible to disable maxima automated simplification ?
Sorry, I thought this was clear. when you type sage: a=x+x+1 sage: a 2*x + 1 If I understood correctly, the simplification of x+x by 2*x is done by maxima in the background. I f x is here much more complicated (or if the expression itself is complicated), the simplification process can become lengthy and even crash maxima. So my question was : is this possible that when I ask a in the second line above, that the answer would be x+x+1 Sorry for the trouble Nicolas On 23 juin, 11:19, William Stein wst...@gmail.com wrote: On Tue, Jun 23, 2009 at 9:40 AM, Nicolasnicolas.fresseng...@gmail.com wrote: I am in the writing of a program that deals with rather lengthy symbolic expressions involving unknown functions and differentiation. When running commands like derivatives, it seems that maxima automatically runs into place to simplify the obtained expressions. (This is consistent with the documentation) In interactive sessions, this is perfectly good, but for my application, it has two major problems : - things are slowed down a lot because maxima tries to simplify long expressions which cannot be much simplified - worse : maxima often crashes which renders the whole program difficult to use My solution would be to disable maxima automated simplification but I cannot figure out if this is possible in sage or how to do it (I am using sage.4.0.1 on Fedora 10) Please provide a much more precise example than what you've given above (which is no examples at all). -- William --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Is it possible to disable maxima automated simplification ?
On Wed, Jun 24, 2009 at 6:47 PM, Nicolasnicolas.fresseng...@gmail.com wrote: Sorry, I thought this was clear. when you type sage: a=x+x+1 sage: a 2*x + 1 If I understood correctly, the simplification of x+x by 2*x is done by maxima in the background. Just to be clear, that is definitely *NOT* the case. It used to be the case before sage-4.0, but is not the case now. Here's how you can check this: teragon:~ wstein$ sage -- | Sage Version 4.0.2, Release Date: 2009-06-18 | | Type notebook() for the GUI, and license() for information.| -- sage: x + x + 1 2*x + 1 sage: Exiting SAGE (CPU time 0m0.08s, Wall time 0m23.29s). You have new mail in /var/mail/wstein teragon:~ wstein$ sage -- | Sage Version 4.0.2, Release Date: 2009-06-18 | | Type notebook() for the GUI, and license() for information.| -- sage: f = integrate(sin(x^2)) sage: Exiting SAGE (CPU time 0m0.16s, Wall time 0m6.97s). Exiting spawned Maxima process. teragon:~ wstein$ Notice that the first time there's no Exiting spawned Maxima process. message. I f x is here much more complicated (or if the expression itself is complicated), the simplification process can become lengthy and even crash maxima. So my question was : is this possible that when I ask a in the second line above, that the answer would be x+x+1 Note that maxima isn't involved. Sorry for the trouble Nicolas On 23 juin, 11:19, William Stein wst...@gmail.com wrote: On Tue, Jun 23, 2009 at 9:40 AM, Nicolasnicolas.fresseng...@gmail.com wrote: I am in the writing of a program that deals with rather lengthy symbolic expressions involving unknown functions and differentiation. When running commands like derivatives, it seems that maxima automatically runs into place to simplify the obtained expressions. (This is consistent with the documentation) In interactive sessions, this is perfectly good, but for my application, it has two major problems : - things are slowed down a lot because maxima tries to simplify long expressions which cannot be much simplified - worse : maxima often crashes which renders the whole program difficult to use My solution would be to disable maxima automated simplification but I cannot figure out if this is possible in sage or how to do it (I am using sage.4.0.1 on Fedora 10) Please provide a much more precise example than what you've given above (which is no examples at all). -- William -- William Stein Associate 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Is it possible to disable maxima automated simplification ?
On Jun 24, 2009, at 10:05 AM, William Stein wrote: On Wed, Jun 24, 2009 at 6:47 PM, Nicolasnicolas.fresseng...@gmail.com wrote: Sorry, I thought this was clear. when you type sage: a=x+x+1 sage: a 2*x + 1 If I understood correctly, the simplification of x+x by 2*x is done by maxima in the background. Just to be clear, that is definitely *NOT* the case. It used to be the case before sage-4.0, but is not the case now. Here's how you can check this: teragon:~ wstein$ sage -- | Sage Version 4.0.2, Release Date: 2009-06-18 | | Type notebook() for the GUI, and license() for information.| -- sage: x + x + 1 2*x + 1 sage: Exiting SAGE (CPU time 0m0.08s, Wall time 0m23.29s). Pynac does perform some simplifications automatically, e.g. the x+x - 2*x. You can read about it here http://www.ginac.de/tutorial/ Automatic-evaluation.html . These are nearly impossible to avoid (I tried to do so for a while when working on powering) but shouldn't ever do anything expensive. As for simplifying an integral, I'm not sure if it's simplified internally by maxima as part of the integration process, or when the result is printed. Have you tried assigning the result to a variable? That would determine if we can do something about it. - Robert --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
[sage-support] Re: Is it possible to disable maxima automated simplification ?
On Tue, Jun 23, 2009 at 9:40 AM, Nicolasnicolas.fresseng...@gmail.com wrote: I am in the writing of a program that deals with rather lengthy symbolic expressions involving unknown functions and differentiation. When running commands like derivatives, it seems that maxima automatically runs into place to simplify the obtained expressions. (This is consistent with the documentation) In interactive sessions, this is perfectly good, but for my application, it has two major problems : - things are slowed down a lot because maxima tries to simplify long expressions which cannot be much simplified - worse : maxima often crashes which renders the whole program difficult to use My solution would be to disable maxima automated simplification but I cannot figure out if this is possible in sage or how to do it (I am using sage.4.0.1 on Fedora 10) Please provide a much more precise example than what you've given above (which is no examples at all). -- William --~--~-~--~~~---~--~~ 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 URLs: http://www.sagemath.org -~--~~~~--~~--~--~---
