Dear Holger,
I have resolved the problem: it was a (rarely occurring?) rounding bug
in \pgfmathdivide. I have just committed the bugfix to pgf CVS.
Its very good that this has been found, so thanks again for reporting it.
If you rely on this feature, and you do not have access to a recent pgf
version (in this case, pgf CVS of April 23, 2011 or newer), I can supply
a bugfix which can be activated by means of something like
\usepackage{bugfixpgf}.
If you have access to a pgf developer version, it suffices to upgrade
pgf and the plot will look as expected.
Best regards
Christian
Am 19.04.2011 09:40, schrieb Holger Maune:
> Hi,
>
> I tried to plot the formula $(1+2x(1+x+25^2x))/(1+4x(1+x+25^2x))$ within a
> semilog axis. I get ripples on the y-values. Here the code:
>
> \documentclass{minimal}
> \usepackage{pgfplots}
> \begin{document}
> \begin{tikzpicture}
> \begin{semilogxaxis}[domain=1e-2:1e3, samples=101]
> \addplot[black] {(1+2*x*(1+x+25^2*x))/(1+4*x*(1+x+25^2*x))};
> \end{semilogxaxis}
> \end{tikzpicture}
> \end{document}
>
> pfgplots 1.4.1 from texlive2010
>
> Any idea, whats going on here?
>
> Thanks
>
> Holger
>
>
> ------------------------------------------------------------------------------
> Benefiting from Server Virtualization: Beyond Initial Workload
> Consolidation -- Increasing the use of server virtualization is a top
> priority.Virtualization can reduce costs, simplify management, and improve
> application availability and disaster protection. Learn more about boosting
> the value of server virtualization. http://p.sf.net/sfu/vmware-sfdev2dev
> _______________________________________________
> Pgfplots-features mailing list
> Pgfplots-features@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/pgfplots-features
------------------------------------------------------------------------------
Fulfilling the Lean Software Promise
Lean software platforms are now widely adopted and the benefits have been
demonstrated beyond question. Learn why your peers are replacing JEE
containers with lightweight application servers - and what you can gain
from the move. http://p.sf.net/sfu/vmware-sfemails
_______________________________________________
Pgfplots-features mailing list
Pgfplots-features@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/pgfplots-features
