I'm trying to plot a normalized sinc function with PGFPlots/TikZ. As this is somewhat tricky because of the limiting value at 0, I used a suggestion provided by percusse.
Here's a minimal example (note that I've renamed the function to sincf
due to conflicts with the rest of the document and inserted an approximation of Pi to normalize):
\documentclass{scrreprt}
\usepackage{pgfplots}
\pgfplotsset{compat=1.12}
\begin{document}
\begin{tikzpicture}
% https://tex.stackexchange.com/a/235009
\pgfmathdeclarefunction{sincf}{1}{%
\pgfmathparse{abs(#1)<0.01 ? int(1) : int(0)}%
\ifnum\pgfmathresult>0 %
\pgfmathparse{1}%
\else%
\pgfmathparse{sin(3.14159*#1 r)/(3.14159*#1)}%
\fi%
}
\begin{axis}
\addplot {sincf(\x)};
\end{axis}
\end{tikzpicture}
\end{document}
However, I'm getting two errors which I can't figure out:
! Missing = inserted for \ifnum.
<to be read again>
Y
l.23 \addplot plot (\x,{sincf(\x)});
I was expecting to see `<', `=', or `>'. Didn't.
! Missing number, treated as zero.
<to be read again>
Y
l.23 \addplot plot (\x,{sincf(\x)});
A number should have been here; I inserted `0'.
(If you can't figure out why I needed to see a number,
look up `weird error' in the index to The TeXbook.)
Using MikTeX 2.9
\pgfmathresult=0Y0.0e0]
, so not a good value for\ifnum
.