# Decorate contour with arrows in different directions

In this post it is thoroughly explained how to decorate a contour with arrows. How can I do the same, but so that one contour has arrows in one direction, and the other contour has arrows in the opposite? The contours are in the same tikzpicture environment. Is it possible to define multiple instances of decorations, perhaps?

You can define multiple markings, and you can reverse either by drawing the path in the reverse direction or by defining the marking with reversed arrows.

\documentclass[border=2mm]{standalone}

\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\tikzset
{marking1/.style=
{decoration=
{markings,
mark=at position 0.5 with {\arrow[line width=1pt]{>}}
},
postaction=decorate
},
marking1reversed/.style=
{decoration=
{markings,
mark=at position 0.5 with {\arrow[line width=1pt]{<}}
},
postaction=decorate
},
marking2/.style=
{decoration=
{markings,
mark=at position 0.33 with {\arrow[line width=1pt]{stealth}},
mark=at position 0.66 with {\arrow[line width=1pt,xscale=-1]{stealth}}
},
postaction=decorate
}
}
\begin{document}
\begin{tikzpicture}
% a path with three sections
\draw[marking1] (0,0) -- (2,0);
\draw[marking1] (2,0) -- (1,1);
\draw[marking1] (1,1) -- (0,0);
% path drawn in the opposite direction, with the same marking
\begin{scope}[xshift=3cm]
\draw[marking1] (0,0) -- (1,1);
\draw[marking1] (1,1) -- (2,0);
\draw[marking1] (2,0) -- (0,0);
\end{scope}
% the original path, but with another marking that reverses the arrows
\begin{scope}[xshift=6cm]
\draw[marking1reversed] (0,0) -- (2,0);
\draw[marking1reversed] (2,0) -- (1,1);
\draw[marking1reversed] (1,1) -- (0,0);
\end{scope}
% the original path with a completely different marking
\begin{scope}[xshift=9cm]
\draw[marking2] (0,0) -- (2,0);
\draw[marking2] (2,0) -- (1,1);
\draw[marking2] (1,1) -- (0,0);
\end{scope}
\end{tikzpicture}
\end{document}

• How can I make it so the stealth arrow is reversed? – Pedro Tamaroff Apr 20 '17 at 18:24
• @PeterTamaroff Using xscale=-1, see my edited answer. – gernot Apr 20 '17 at 18:29
• Great. This is exactly what I needed. – Pedro Tamaroff Apr 20 '17 at 20:13