ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Thu, 29 Aug 2013 06:43:36 +0200Why does jordan_form not work over inexact rings?https://ask.sagemath.org/question/10488/why-does-jordan_form-not-work-over-inexact-rings/Hi,
Given a matrix M with entries (variables) in SR, I needed to compute the transformation matrix to a jordan form of M.
I ended up copying the code in "jordan_form" and "_jordan_form_vector_in_difference" from "matrix2.pyx",
deleting the "if (base_ring is None and not self.base_ring().is_exact()) ..."
and replacing "evals = A.charpoly().roots()" by
eigenvects=A.eigenvectors_right()
evals=[(eigenvect[0],eigenvect[2]) for eigenvect in eigenvects]
So far it seems to work. Can this go wrong? Or could one just change the original code in matrix2.pyx, and allow inexact rings?
Thanks for your help!LolinaThu, 29 Aug 2013 06:43:36 +0200https://ask.sagemath.org/question/10488/I need help with Sagetex/Sage (normal form&data file useage)https://ask.sagemath.org/question/7739/i-need-help-with-sagetexsage-normal-formdata-file-useage/Greetings!
I have two questions.
The easier is, how can i "ask" Sagemath to numerically calculate, and use normal form. For example i would like to see sqrt{2}/10 as 1.41 * 10^{-1}. It would be useful to always get the same precision. Like 2/10 as 2.00 * 10^{-1}
The harder question is, i want to make several calculations with the same data (about 10-20 lines, every line with 2-4 records). It is possible to copy and paste it every time, but i rather do it an easier way. Is it possible?
DanielDaniel BalogWed, 27 Oct 2010 19:19:13 +0200https://ask.sagemath.org/question/7739/