# What causes a custom path with linearc to have asymmetrical ripple?

The objective is to make the bottom of a bullet has rounded corners. What I don't understand are:

• Why does the ripple only occur on the bottom part but not on the top part even though the bottom one is just a reflection of the top one?

• Why does the ripple occur for a specific value of linearc?

• How to fix this problem?

\documentclass[pstricks]{standalone}
\usepackage{pst-plot}

\def\bottom{\psparametricplot{0}{2}{-t^2+6|t}\psline(1,2)}

\begin{document}
\multido{\n=0.7+0.1}{5}{%
\begin{pspicture}[algebraic](-5,-6)(7,3)
\pscustom[fillstyle=solid,fillcolor=gray,linewidth=2pt,linearc=\n pt]
{
\bottom
\reversepath
\scale{1 -1}
\bottom
\closepath
}
\rput[tl](-4,2){\tt linearc=\n pt}
\end{pspicture}}

\end{document}


-

I'm not sure about the source of the problem. However, here is a fix for it :)

\documentclass[pstricks]{standalone}
\usepackage{pst-plot}

\def\bottom{\psparametricplot{0}{2}{-t^2+6|t}\psline(1,2)}

\begin{document}
\multido{\n=0.1+0.1}{50}{%
\begin{pspicture}[algebraic](-5,-6)(7,3)
\pscustom[fillstyle=solid,fillcolor=gray,linewidth=2pt,linearc=\n pt]
{
\bottom
\reversepath
\scale{1 -1}
\rlineto(0,-0.001)
\bottom
\closepath
}
\rput[tl](-4,2){\tt linearc=\n pt}
\end{pspicture}}
\end{document}


-
It seems linearc has no effect for pscustom. – kiss my armpit May 13 '14 at 21:27