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.Tue, 27 Dec 2016 23:58:06 +0100Variable overrites function defined previouslyhttps://ask.sagemath.org/question/36108/variable-overrites-function-defined-previously/I have u(t) which is an function of t, and g(u) which is a function of u. I want to find the derivative of g(u)*u(t) w.r.t. t.
sage: u(t) = function('u')(t)
sage: h(u) = function('h')(u)
sage: u
u
sage: h
u |--> h(u)
diff(h(u)*u(t),t)
h(u)
This seems to happen because the function u is overwritten when I use u to define the function h. I can get around it this way.
sage: u(t) = function('u')(t)
sage: h(x) = function('h')(x)
sage: u
t |--> u(t)
sage: h
x |--> h(x)
sage: diff(h(u)*u(t),t)
u(t)*D[0](h)(u(t))*D[0](u)(t) + h(u(t))*D[0](u)(t)
Can this be classified as a bug?
If it is, would it be possible to fix it?
Thanks in advance.omoplataTue, 27 Dec 2016 23:58:06 +0100https://ask.sagemath.org/question/36108/save (and reuse) parametric_plot3d objecthttps://ask.sagemath.org/question/24390/save-and-reuse-parametric_plot3d-object/Hello,
I am a total newbie in Sage and I do not talk Python :-(
I was just trying to draw some surfaces for illustration when I came across a problem loading my saved computations.
NotImplementedError: You must override the get_grid method.
(code below.)
Is there a way to do what is suggested (override...)?
I found a bug ticket
[http://trac.sagemath.org/ticket/9957](http://trac.sagemath.org/ticket/9957)
and saw
[http://ask.sagemath.org/question/7704/importing-saved-3d-plot/](http://ask.sagemath.org/question/7704/importing-saved-3d-plot/)
I am not very hopeful, but since I basically do not understand what's written, maybe there's a way to override get-grid as the error message says.
Is there?
If not, is there a way to convert to an object that can be saved (and at least displayed again) or export it to an external format?
Thank you,
bb16
code:
sage: pam2=load(DATA+'pam2imt5000.sobj')
sage: type(pam2)
<html><script type="math/tex">\newcommand{\Bold}[1]{\mathbf{#1}}\verb|<type|\phantom{\verb!x!}\verb|'sage.plot.plot3d.parametric_surface.ParametricSurface'>|</script></html>
sage: show(pam2)
Traceback (most recent call last):
...
NotImplementedError: You must override the get_grid method.
sage: load(DATA+'pam3imt5000.sobj')
Traceback (most recent call last):
...
NotImplementedError: You must override the get_grid method.
bb16Sat, 04 Oct 2014 11:36:58 +0200https://ask.sagemath.org/question/24390/