# Arrows on Circle

Hello i'm trying to get the arrows on the circles

\documentclass{article}
\usepackage{pstricks}
\usepackage{pst-all}
\begin{document}
\begin{pspicture}(-4,-4)(4,4)\grilla
\psaxes[linewidth=1.2pt,labels=none,
ticks=none]{-}(0,0)(-4,-4)(4,4)
\pscircle[linewidth=1.1pt](0,0){1}
\pscircle[linewidth=1.1pt](0,0){2}
\pscircle[linewidth=1.1pt](0,0){3}
\rput[c](4,0.2){$x$}
\rput[c](0.2,3.8){$y$}
\end{pspicture}

\end{document}
• Your code does not compile. What is \grilla? – Phelype Oleinik Jan 11 '18 at 15:41
• \grilla is grid... \newpsobject{grilla}{psgrid}{subgriddiv=1,griddots=10,gridlabels=6pt} – ChuckTesta Jan 11 '18 at 16:39

\documentclass{article}
\usepackage{pst-plot}
\begin{document}

\begin{pspicture}(-4,-4.5)(4,4.5)
\psaxes[labels=none,ticks=none]{->}(0,0)(-4,-4)(4,4)[$x$,0][$y$,90]
\psset{arrowscale=1.5}
\multido{\n=1+1}{3}{%
\psarcn[linewidth=1.1pt]{>->}(0,0){\n}{45}{225}
\psarc[linewidth=1.1pt](0,0){\n}{30}{230}}
\end{pspicture}

\end{document}

• Do you know why the radii of arcs and circles get treated differently? – user121799 Jan 11 '18 at 16:33
• I cannot see that behaviour – user2478 Jan 11 '18 at 16:37
• Please have a look at my example below and compile it with  \psarc[linewidth=1.1pt]{<-}(0,0){\n}{45}{90} instead of  \psarc[linewidth=1.1pt]{<-}(0,0){\rad}{45}{90}. (I had to reduce the radii of the arcs by 1.1pt in order to have them sit on the circles.) – user121799 Jan 11 '18 at 17:03
• @marmot: What do you mean "the radii of arcs and circles get treated differently"? They are different in what? You can play with dimen to avoid such a difference. – Money Oriented Programmer Jan 11 '18 at 18:58
• @marmot: use dimen=middle for the circle – user2478 Jan 11 '18 at 19:17

Also with tikz:

\documentclass[border=2pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.markings,bending}

\begin{document}
\begin{tikzpicture}[>=latex,line width=.7pt]
\draw (-3.2,0)--(3.2,0)node[right]{$x$} (0,-3.2)--(0,3.2)node[above]{$y$};
\foreach \r in {1,2,3}
\draw[
decoration={markings, mark=at position 0.125 with {\arrow{<}}},
decoration={markings, mark=at position 0.625 with {\arrow{<}}},
postaction={decorate}
]
(0,0) circle (\r);
\end{tikzpicture}
\end{document}

Thanks to Herbert, there is a very simple solution:

\documentclass{article}
\usepackage{pstricks}
\usepackage{pst-all}
\begin{document}
\begin{pspicture}(-4,-4)(4,4)%\grilla
\psaxes[linewidth=1.2pt,labels=none,
ticks=none]{-}(0,0)(-4,-4)(4,4)
\multido{\n=1+1}{3}{
\pscircle[dimen=middle,linewidth=1.1pt](0,0){\n}
\psarc[linewidth=1.1pt]{<-}(0,0){\n}{45}{90}
\psarc[linewidth=1.1pt]{<-}(0,0){\n}{225}{270}}

\rput[c](4,0.2){$x$}
\rput[c](0.2,3.8){$y$}
\end{pspicture}
\end{document}

The dimen=middle is required since otherwise the radii of the arcs and circles disagree.

If the aim is to really reproduce the arrows from your picture, you may also use

\documentclass{article}
\usepackage{pstricks}
\usepackage{pst-all}
\begin{document}
\begin{pspicture}(-4,-4)(4,4)%\grilla
\psaxes[linewidth=1.2pt,labels=none,
ticks=none]{-}(0,0)(-4,-4)(4,4)
\def\mytriangle{\begin{pspicture}(-0.2,-0.2)(0.2,0.2)
\pspolygon[fillstyle=solid,fillcolor=black](-0.2,0.2)(0.2,0.2)(0,-0.2)
\end{pspicture}
}

\multido{\n=1+1}{3}{
\pscircle[linewidth=1.1pt](0,0){\n}
\pstFPmul\rad{\n}{0.707107} % 0.707107 = 1/sqrt(2)
}

\rput[c](4,0.2){$x$}
\rput[c](0.2,3.8){$y$}
\end{pspicture}

\end{document}

I'd be very interested to learn to reproduce the nice curved arrows that come with the feynmp package (curved fermion lines) with either pstricks or tikZ.

UPDATE Using AboAmmar's solution and this answer, one can may bend the arrows.

\documentclass[border=2pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.markings,bending,arrows.meta,calc}

\begin{document}
\begin{tikzpicture}[>=latex,line width=.7pt]
\draw (-3.2,0)--(3.2,0)node[right]{$x$} (0,-3.2)--(0,3.2)node[above]{$y$};
\foreach \r in {1,2,3}
{\draw      (0,0) circle (\r);
\draw[-{Stealth[length=0.3cm,bend]}]  (90:\r) arc (90:45:\r);
\draw[-{Stealth[length=0.3cm,bend]}]  (270:\r) arc (270:225:\r);}
\end{tikzpicture}
\end{document}

• @ArtificialStupidity I know and it produced a weird output, please try yourself. (It skipped one circle.) – user121799 Jan 11 '18 at 18:57
• @ArtificialStupidity That's a matter of taste. Unlike TikZ, pstricks is perfectly fine with nested picture environments, and my command can also be called outside the picture, – user121799 Jan 11 '18 at 19:10
• As I said in my comment to Herbert's answer, play with dimen. Anyway, dimen=m is enough. Thanks to me. :-) – Money Oriented Programmer Jan 11 '18 at 19:40