# Can't add square root symbol in Geonode Name

I'm a beginner with LaTex and i'm stuck with the following error.

http://prntscr.com/lcc8re

What i'm trying to do is have a point (i'm using the Geonode from the pst-euclide package) that looks like this http://prntscr.com/lcca67

I don't understand my mistake, it seems that any combination of formula that contains a square root isn't acceptable as a name for the node

Here's my code

\documentclass[pstricks,border=12pt]{standalone}
\usepackage{pst-plot}
\usepackage{pst-eucl}
\usepackage{auto-pst-pdf}

\begin{pspicture}(-1.5,-1.5)(1.5,1.5)

\psaxes[linecolor=gray,tickcolor=gray,labels=none]{->}(0,0)(-1.5,-1.5)(1.5,1.5)[$r$,0][$i$,90]
\pscircle(0,0){1}
\pstGeonode[PtNameMath=false,PointName={$e^{j\varphi}$},PosAngle=45](0.5,0.866){A}
\pstGeonode[PtNameMath=false,PointName={$\sqrt{3}$},PosAngle=-45](0.5,-0.866){B}
\pstGeonode[PtNameMath=false,PointName={$e^{j\varphi}$},PosAngle=135](-0.5,0.866){C}
\pstGeonode[PtNameMath=false,PointName={$e^{j\varphi}$},PosAngle=-135](-0.5,-0.866){D}

\pcline[linestyle=dashed,linecolor=gray,linewidth=0.5pt](A)(B)
\pcline[linestyle=dashed,linecolor=gray,linewidth=0.5pt](C)(D)

\end{pspicture}

\end{document}


Thanks a lot for the help

• You missed \begin{document} Oct 30 '18 at 17:40

\sqrt seems to confuse pstricks.

\documentclass{article}
\usepackage{pst-plot}
\usepackage{pst-eucl}
\usepackage{auto-pst-pdf}
\usepackage{etoolbox}

\robustify\sqrt

\begin{document}

\begin{pspicture}(-1.5,-1.5)(1.5,1.5)
\psaxes[linecolor=gray,tickcolor=gray,labels=none]{->}(0,0)(-1.5,-1.5)(1.5,1.5)[$r$,0][$i$,90]
\pscircle(0,0){1}
\pstGeonode[PtNameMath=false,PointName={$e^{j\varphi}$},PosAngle=45](0.5,0.866){A}
\pstGeonode[PtNameMath=false,PointName={$\sqrt{3}$},PosAngle=-45](0.5,-0.866){B}
\pstGeonode[PtNameMath=false,PointName={$e^{j\varphi}$},PosAngle=135](-0.5,0.866){C}
\pstGeonode[PtNameMath=false,PointName={$e^{j\varphi}$},PosAngle=-135](-0.5,-0.866){D}
\pcline[linestyle=dashed,linecolor=gray,linewidth=0.5pt](A)(B)
\pcline[linestyle=dashed,linecolor=gray,linewidth=0.5pt](C)(D)
\end{pspicture}

\end{document}


An alternative to @egreg's nice answer without etoolbox.

\documentclass[pstricks,border=12pt]{standalone}
\usepackage{pst-plot}
\usepackage{pst-eucl}
\usepackage{auto-pst-pdf}
\newsavebox\tmpbox
\sbox\tmpbox{$\sqrt{3}$}
\begin{document}
\begin{pspicture}(-1.5,-1.5)(1.5,1.5)
\psaxes[linecolor=gray,tickcolor=gray,labels=none]{->}(0,0)(-1.5,-1.5)(1.5,1.5)[$r$,0][$i$,90]
\pscircle(0,0){1}
\pstGeonode[PtNameMath=false,PointName={$e^{j\varphi}$},PosAngle=45](0.5,0.866){A}
\pstGeonode[PtNameMath=false,PointName={$\usebox\tmpbox$},PosAngle=-45](0.5,-0.866){B}
\pstGeonode[PtNameMath=false,PointName={$e^{j\varphi}$},PosAngle=135](-0.5,0.866){C}
\pstGeonode[PtNameMath=false,PointName={$e^{j\varphi}$},PosAngle=-135](-0.5,-0.866){D}

\pcline[linestyle=dashed,linecolor=gray,linewidth=0.5pt](A)(B)
\pcline[linestyle=dashed,linecolor=gray,linewidth=0.5pt](C)(D)
\end{pspicture}
\end{document}