1

I want the arrow to scale with the arc scale. See my example below. You will notice that the arrow looks fine as long as the arc radius is large. 

\documentclass[crop,tikz]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows,shapes}

\begin{document}

\tikzset{
    pics/carc/.style args={#1:#2:#3}{
        code={
            \draw[pic actions] (#1:#3) arc(#1:#2:#3);
        }
    }
}

\begin{tikzpicture}
    \draw[thick] (4,2)  pic[red, -latex]{carc=10:290:0.2cm};
     \draw[thick] (8,2)  pic[red, -latex]{carc=10:290:1.2cm};

\end{tikzpicture}

\end{document}

enter image description here

CroCo
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Dipole
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  • 8
  • 17

1 Answers1

2

Load the bending library:

\documentclass[crop,tikz]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows,shapes,bending}

\begin{document}

\tikzset{
    pics/carc/.style args={#1:#2:#3}{
        code={
            \draw[pic actions] (#1:#3) arc(#1:#2:#3);
        }
    }
}

\begin{tikzpicture}
    \draw[thick] (4,2)  pic[red, -latex]{carc=10:290:0.2cm};
     \draw[thick] (8,2)  pic[red, -latex]{carc=10:290:1.2cm};

\end{tikzpicture}

\end{document}

enter image description here

Gonzalo Medina
  • 505,128
  • Thanks! But just one question- if I go below 0.2cm radius there is still the same problem. Why wouldn't bending correct this too? – Dipole Oct 15 '15 at 18:38
  • @Jack 0.2cm is 2mm. Below this, do you really need an arc with an arrow so small? For such cases, perhaps better to use a decoration. – Gonzalo Medina Oct 15 '15 at 18:41
  • Well ideally yes, but I think I can make do with this! I was more just wondering why there would be a limit on the scale of the thing I am drawing, unless it has something to do with the printing hardware (on a computer you can always zoom to an appropriate scale right?) – Dipole Oct 15 '15 at 18:43
  • 1
    @Jack As I mentioned in my previous comment (perhaps you didn't read the final part that I just added), a decoration could be used to treat those cases. – Gonzalo Medina Oct 15 '15 at 18:46