[Tex/LaTex] Distance between arrow and text above arrow in tikz

tikz-pgf

I am drawing two nodes and an arrow between these nodes with

\documentclass[tikz,border=5pt]{standalone}

\usetikzlibrary{positioning}

\begin{document}

\begin{tikzpicture}[node distance=5cm]

% nodes
\node [draw] (A) {A};
\node [draw, right=of A] (B) {B};

% arrows
\draw [->] (A) -- node [above, midway] {Some text} (B);

\end{tikzpicture}

\end{document}

Using \draw [->] (A) -- node [above, midway] {Some text} (B); I can write text above the arrow; however, the text doesn't respect the configured node distance. Can I set the distance between the arrow and the text?

Best Answer

You will have to shift the label. They are not controlled by the node distance.

Chose one approach:

% arara: pdflatex

\documentclass[tikz,border=5pt]{standalone}
\usetikzlibrary{positioning}

\begin{document}    
    \begin{tikzpicture}[node distance=5cm]
    \node [draw] (A) {A};
    \node [draw, right=of A] (B) {B};
    \node [draw, right=of B] (C) {C};
    \node [draw, right=of C] (D) {D};
    \draw [->] (A) -- node [above=5cm] {Some text} (B); 
    \draw [->] (B) -- node [label={[yshift=5cm]Some text}] {} (C);  
    \draw [->] (C) -- node [label={[label distance=5cm]90:Some text}] {} (D);   
    \end{tikzpicture}   
\end{document}

The one you like, you might apply be adding e.g. \begin{tikzpicture}[every label/.append style={above=5cm}]

Related Solutions

[Tex/LaTex] Rotate a node but not its content: the case of the ellipse decoration

The source of the difficulty is that ellipses are constructed in a particular way in TikZ. They are paths that start from the x-axis and proceed counter-clockwise around their centre. The vast majority of the time, the exact parametrisation doesn't matter. You appear to have found the one situation where it does!

In the actual question, you only want to be able to mirror the ellipse, and so draw it starting from the negative x-axis (the title of the question suggests a more flexible approach). That's actually not too hard since we can exploit the symmetry of the ellipse. The key is to provide it with a negative x-radius, since then it will start from the negative x-axis (and proceed clockwise, but we could correct for that by negating the y-radius as well). To do this, we interrupt the call from the node shape to the drawing command and flip the sign of the x-radius. The simplest way to do this is to redefine the \pgfpathellipse macro to do the negation and then call the original macro. The following code does this.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{decorations,shapes,decorations.markings}
\makeatletter
\let\origpgfpathellipse=\pgfpathellipse
\def\revpgfpathellipse#1#2#3{%
  #2%
  \pgf@xa=-\pgf@x
  \origpgfpathellipse{#1}{\pgfqpoint{\pgf@xa}{0pt}}{#3}}
\makeatother

\tikzset{
  reversed ellipse/.style={
    ellipse,
    reverse the ellipse%
  },
  reverse the ellipse/.code={
    \let\pgfpathellipse=\revpgfpathellipse
  }
}
\begin{document}
\begin{tikzpicture}
\node[ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,0) {hello world};

\node[reversed ellipse,
  draw,
  postaction={
    decorate,
    decoration={
      markings,
      mark=at position 1 with {
        \arrow[line width=5pt,blue]{>}
      }
    }
  }
] at (0,-2) {hello world};
\end{tikzpicture}

\end{document}

Here's the result:

rotated ellipse

(the arrow got clipped, but you can see where it lies)

[Tex/LaTex] Controlling arrow distance from the destination node in TikZ

Well, I don't know why it is happening but I know where it is happening. The arrowhead stealth' is the culprit and amazingly it gets affected by the line

\renewcommand{\baselinestretch}{2}

regardless of the amount put inside the definition. ~~You don't see that with other arrow heads.~~ It happens with arrows library specific arrows. Here is a much simpler MWE (I wish you did this for us but anyway)

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows}
\begin{document}

\begin{tikzpicture}
\node[draw] (A) {$q_a$};
\node[draw] (B) at (1,0) {a};
\draw[-stealth'](A) -- (B);
\end{tikzpicture}

\renewcommand{\baselinestretch}{2}

\begin{tikzpicture}
\node[draw] (A) {$q_a$};
\node[draw] (B) at (1,0) {a};
\draw[-stealth'](A) -- (B);
\end{tikzpicture}
\end{document}

enter image description here

David Carlisle also indicated that there is a font selection issue or absence of it for reasons beyond me. Hence,

\renewcommand{\baselinestretch}{2}\selectfont

brings the arrow back to the node border. But I don't know what it breaks....

Long story short this is very likely to be related to the way how \nullfont declaration is invoked. For example, putting \selectfont\nullfont as the first code inside the TikZ picture also removes the artifact. So at some point before TikZ starts to do its job font selection should be finished so that one can switch to the \nullfont properly.

Thus, David's comment below is very important.

Best Answer

Related Solutions

[Tex/LaTex] Rotate a node but not its content: the case of the ellipse decoration

[Tex/LaTex] Controlling arrow distance from the destination node in TikZ

Related Question