5

In tikz, I can make an arrow connecting two nodes with straight lines and a 90 degree corner by using |- or -|. But is there an easy way to make a straight horizontal/vertical segment and then a 45 degree (or radially inward or some other angle) segment, like the red line in the figure?

\documentclass[12pt]{extarticle}
\usepackage[paperwidth=7.4cm, paperheight=5.55cm, top=0cm, bottom=0cm, left=0cm, right=0cm]{geometry}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,positioning,calc}
\tikzstyle{circle1} = [draw, circle, minimum size = 1.5mm]

\begin{document}
\begin{tikzpicture}[auto, node distance = 1.2cm]
        \node (first) [circle1] {first};
        \node (second) [circle1, right of = first, node distance = 3.5 cm, below=2.5 cm] {second};

        \draw[->, thick] (first.0) -- node [above] {$--$} (second.135);
        \draw[->, thick] (first.0) |- node [below] {$|-$} (second.160);
\end{tikzpicture}
 \end{document}

Output from sample code with desired addition in red

EL_DON
  • 231

2 Answers2

4
\documentclass[12pt]{extarticle}
\usepackage[paperwidth=8.6cm, paperheight=5.55cm, top=0cm, bottom=0cm, left=0cm, right=0cm]{geometry}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,positioning,calc}
\tikzset{circle1/.style={draw, circle, minimum size = 1.5mm}}
\tikzset{pics/perp/.style={code={\draw[-] (0,0) -- (1,0) (0,-0.5) -- (0,0.5);}},
pics/line/.style={code={\draw[-] (0,0) -- (1,0);}}}

\begin{document}
\begin{tikzpicture}[auto]
        \node (first) [circle1] {first};
        \node (second) [circle1, below right=1.5cm and 5.5cm of first] {second};
        \draw[->, thick] (first.0) -- pic[yshift=3mm,scale=0.3]{line} (second.135);
        \draw[->, thick] (first.0) |- pic[yshift=-3mm,scale=0.3]{perp} (second.160);
        \draw[->, thick,red] let \p1=(first.east), \p2=(second.120) in
        (first.east) -- ++({\x2-\x1-\y1+\y2},0) -- (second.120);
\end{tikzpicture}
\end{document}

enter image description here

After the suggestion by EL_DON to generalize: here is a version with an edge style.

\documentclass[12pt]{extarticle}
\usepackage[paperwidth=8.6cm, paperheight=5.55cm, top=0cm, bottom=0cm, left=0cm, right=0cm]{geometry}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,positioning,calc}
\tikzset{circle1/.style={draw, circle, minimum size = 1.5mm}}
\tikzset{pics/perp/.style={code={\draw[-] (0,0) -- (1,0) (0,-0.5) -- (0,0.5);}},
pics/line/.style={code={\draw[-] (0,0) -- (1,0);}}}


\begin{document}

\begin{tikzpicture}[auto,connect with angle/.style=
{to path={let \p1=(\tikztostart), 
\p2=(\tikztotarget) in -- ++({\x2-\x1-(\y1-\y2)*tan(#1-90)},0) -- (\tikztotarget)}}]
        \node (first) [circle1] {first};
        \node (second) [circle1, below right=1.5cm and 5.5cm of first] {second};
        \draw[->, thick] (first.0) -- pic[yshift=3mm,scale=0.3]{line} (second.135);
        \draw[->, thick] (first.0) |- pic[yshift=-3mm,scale=0.3]{perp} (second.160);
        \draw[red,-latex] (first.east) edge[connect with angle=135] (second.120);
        \draw[blue,-latex] (first.east) edge[connect with angle=105] (second.120);
\end{tikzpicture}
\end{document}

enter image description here

Here, by EL_DON's convention, the angle is the angle between the two stretches. Other conventions may be accounted for by adjusting tan(#1-90) appropriately.

  • 1
    You could generalize this by defining \newcommand\exitangle{135} and then changing ({\x2-\x1-\y1+\y2},0) to ({\x2-\x1-(\y1-\y2)*tan(\exitangle-90)},0) and also using \exitangle in contexts like \p2=(second.\exitangle). – EL_DON Jun 28 '18 at 20:37
  • 1
    @EL_DON I added a generalization, hope it is OK. ;-) –  Jun 28 '18 at 21:07
  • 1
    That's great. Setting up connect with angle like this would be a lot cleaner in a picture that needed several of these angled arrows. – EL_DON Jun 28 '18 at 21:16
3

with use of intersections library:

\documentclass[tikz, margin=4mm]{standalone}
\usetikzlibrary{intersections,
                positioning,
                shapes}
\tikzstyle{circle1} = [draw, circle, minimum size = 1.5mm]

\begin{document}
    \begin{tikzpicture}[auto,
node distance = 11mm and 22mm]
\node (first) [circle1] {first};
\node (second) [circle1, below right=of first] {second};
%
\draw[->, thick] (first) -- node [above] {$--$} (second);
\draw[->, thick] (first) |- node [below] {$|-$} (second);
%
\path[name path=A] (first) -- (first -| second);
\path[name path=B] (second) -- ++ (135:33mm);
\draw [name intersections={of=A and B, by=a},very thick, blue]
    (first) -- (a) -- (second);
\end{tikzpicture}
 \end{document}

enter image description here

Zarko
  • 296,517