ASKSAGE: Sage Q&A Forum - Individual question feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Sat, 31 Dec 2011 22:32:06 -0600Differentiation of a power series.https://ask.sagemath.org/question/8334/differentiation-of-a-power-series/I wonder whether it is too hard to implement the derivative function for multivariate Power Series Ring. Since it is already implemented for one variable, is it not possible to implement it for multivariable, by treating the ring in one var over the ring in other vars.
e.g.
QQ[[x,y,z]] = QQ[[x,y]][z]]
Thanks and regards
--VInayTue, 20 Sep 2011 02:07:06 -0500https://ask.sagemath.org/question/8334/differentiation-of-a-power-series/Answer by Volker Braun for <p>I wonder whether it is too hard to implement the derivative function for multivariate Power Series Ring. Since it is already implemented for one variable, is it not possible to implement it for multivariable, by treating the ring in one var over the ring in other vars.</p>
<p>e.g.</p>
<p>QQ[[x,y,z]] = QQ[[x,y]][z]]</p>
<p>Thanks and regards</p>
<p>--VInay</p>
https://ask.sagemath.org/question/8334/differentiation-of-a-power-series/?answer=13081#post-id-13081This is now <a href="http://trac.sagemath.org/sage_trac/ticket/12241">ticket #12241</a>Sat, 31 Dec 2011 01:17:38 -0600https://ask.sagemath.org/question/8334/differentiation-of-a-power-series/?answer=13081#post-id-13081Comment by VInay Wagh for <p>This is now <a href="http://trac.sagemath.org/sage_trac/ticket/12241">ticket #12241</a></p>
https://ask.sagemath.org/question/8334/differentiation-of-a-power-series/?comment=20608#post-id-20608Hi Volker,
Thanks for the patch. I tried to apply the patch using hg_sage.apply('filename'). It did not give me any error (however gave an irrelevant warning about .sagerc file).
But the code
sage: T.<a,b> = PowerSeriesRing(ZZ,2)
sage: f = a + b + a^2*b
sage: f = a + b + a^2*b + T.O(4)
sage: f.derivative(a)
Gives
NotImplementedError
Traceback (most recent call last)
Do I have to install something more to make this patch work?
-- VInaySat, 31 Dec 2011 22:32:06 -0600https://ask.sagemath.org/question/8334/differentiation-of-a-power-series/?comment=20608#post-id-20608