| Singular https://www.singular.uni-kl.de/forum/ |
|
| Q2: Odd behavior for poly input https://www.singular.uni-kl.de/forum/viewtopic.php?f=10&t=1354 |
Page 1 of 1 |
| Author: | Justin C. Walker [ Thu Aug 11, 2005 5:31 pm ] |
| Post subject: | Q2: Odd behavior for poly input |
Hi, I don't get this: > ring Fp=5,x,dp; > poly f=7*x^3+9*x^2+8*x+3; // ** redefining f ** > f; 2*x^3-x^2-2*x-2 > poly f=7x^3+9x^2+8x+3; // ** redefining f ** > f; -2*x^3+x^2-2*x-2 This is from 2.0.3 (Mac OS X 10.2.4). 'short=0' has been entered. The only difference between the two copies of 'f' is that I didn't use the '*' between coefficient and indeterminate. The second seems wrong to me, while the first seems correct. Help! Regards, Justin email: justin@mac.com Posted in old Singular Forum on: 2003-04-10 03:36:32+02 |
|
| Author: | greuel [ Thu Sep 08, 2005 11:48 am ] |
| Post subject: | |
As 7x^3 is not unique (there are no brackets) there must be a default: 7x^3 = (7x)^3, 7*x^3 = 7*(x^3). The reason is that in Singular 7x is a monomial (taken to the 3rd power) while 7*x is 7 * the monomial x (taken to the 3rd power). To be on the safe side you can always use brackets. This is explained in the Manual: 6.3 Miscellaneous oddities Gert-Martin email: greuel@mathematik.uni-kl.de Posted in old Singular Forum on: 2003-04-15 22:21:56+02 |
|
| Author: | Justin C. Walker [ Wed Sep 21, 2005 8:27 pm ] |
| Post subject: | |
> The reason is that in Singular 7x is a monomial (taken to > the 3rd power) while 7*x is 7 * the monomial x (taken to > the 3rd power). > To be on the safe side you can always use brackets. That's counter-intuitive. I guess I need to go back and read up on what a monomial is. I'd naturally expect '*' (implicit or not) to bind less tightly than '^'. > This is explained in the Manual: > 6.3 Miscellaneous oddities I looked at this section, but just didn't make the connection. Thanks for the clarification. Regards, Justin email: justin@mac.com Posted in old Singular Forum on: 2003-04-16 21:05:37+02 |
|
| Page 1 of 1 | All times are UTC + 1 hour [ DST ] |
| Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/ |
|