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.Wed, 21 Sep 2016 16:46:11 +0200Errors when plotting zeta function parametricallyhttps://ask.sagemath.org/question/34882/errors-when-plotting-zeta-function-parametrically/ I have the following piece of code:
def f(x):
return(real_part(zeta(1+x*I)).n())
def g(x):
return(imag_part(zeta(1+x*I)).n())
parametric_plot([f(x),g(x)], (x,2,10))
It should be moderately clear what I'm trying to do - I want to produce a plot of Riemann zeta function on the line Re(z)=1 using parametric plotting. However, when I try to plot this, I get an error `TypeError: cannot evaluate symbolic expression numerically`. I also tried the same thing without the `.n()`, but then I get an error `TypeError: unable to coerce to a real number`. I couldn't find any help online.
It's worth noting that trying to plot function f(x) I get the same error with `.n()`, but it works just fine without it (as opposed to parametric plot). Does anyone have an idea how to fix the issue?
Thanks in advance.WojowuWed, 21 Sep 2016 16:46:11 +0200https://ask.sagemath.org/question/34882/Solving zeta function equation numericallyhttps://ask.sagemath.org/question/33605/solving-zeta-function-equation-numerically/ I'm trying to solve the equation
$$ \zeta'(x)/\zeta(x) = - 3/4 $$
numerically. I'm expecting/hoping for an answer between 1 and 10.
I tried
$\texttt{ find_root(diff(zeta(x))/zeta(x) + 0.75, 2, 40)}$,
but this returns 0.0. I don't know what that ratio of zeta functions looks like, so it's possible there isn't a root, but I don't see why I'm getting an answer outside the specified interval.
Can anyone help find the true root? Thanks.
ec92Wed, 01 Jun 2016 01:07:50 +0200https://ask.sagemath.org/question/33605/