1segment orientation -1 2\documentclass[tikz]{standalone} 3 4\usepackage{pgflibraryshapes} 5\usetikzlibrary{backgrounds} 6\usetikzlibrary{arrows} 7\begin{document} 8\begin{tikzpicture}[scale = 0.5,font=\fontsize{8}{8}\selectfont] 9\path (2.) node(1_0) [draw,shape=circle,color=gray] {1}; 10\path (-2.) node(2_0) [draw,shape=circle,color=gray] {2}; 11\draw[color=gray] (2_0) -- (1_0); 12\path (0.) node(0_0) [] {}; 13\end{tikzpicture} 14\end{document} 15segment orientation 0 16\documentclass[tikz]{standalone} 17 18\usepackage{pgflibraryshapes} 19\usetikzlibrary{backgrounds} 20\usetikzlibrary{arrows} 21\begin{document} 22\begin{tikzpicture}[scale = 0.5,font=\fontsize{8}{8}\selectfont] 23\path (-2.) node(1_0) [draw,shape=circle,color=gray] {1}; 24\path (2.) node(2_0) [draw,shape=circle,color=gray] {2}; 25\draw[color=gray] (1_0) -- (2_0); 26\path (0.) node(0_0) [] {}; 27\end{tikzpicture} 28\end{document} 29