[Tex/LaTex] Specific arrow tip style for specific path

tikz-pgf

\documentclass[12pt]{article}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}

\begin{document}

\begin{tikzpicture}[scale=1.5,cap ,color= blue] 

% grid
\draw[very thin,color = green,step = 0.5 cm, opacity= 0.9](0,0) grid (4, 4);

% axis 
\draw[->]  [blue,  thick] ( 0,0) --( 4,0) node[right] {$x$};
\draw[->]  [blue,  thick] ( 0,0) --( 0,4) node[above] {$y$};
% how to change the arrow tip style at specific path
% how to set up unique arrow head as a decoration at (1,0) coordinate and at (0,1) 
\draw[decoration={markings, mark=at position 0.5 with {\arrow [ ultra thick] {>}}},
       postaction={decorate}]
        (0,0)--( 2,0);
\draw[decoration={markings, mark=at position 0.5 with {\arrow [ ultra thick] {>}}},
       postaction={decorate}]
        (0,0)--( 0,2);
\end{tikzpicture}
\end{document}

Best Answer

You can replace the > with the desired type of arrow. Below I used the latex and stealth type of arrow in the first image. Alternatively, you can leave the > and apply \tikzset{>=latex} which will replace all > with a latex style arrow as in the second image:

enter image description here

Code:

\documentclass[12pt]{article}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\tikzset{>=latex} 

\begin{document}

\begin{tikzpicture}[scale=1.5,cap=0.5 ,color= blue] 

% grid
\draw[very thin,color = green,step = 0.5 cm, opacity= 0.9](0,0) grid (4, 4);

% axis 
\draw[->]  [blue,  thick] ( 0,0) --( 4,0) node[right] {$x$};
\draw[->]  [blue,  thick] ( 0,0) --( 0,4) node[above] {$y$};
% how to change the arrow tip style at specific path
% how to set up unique arrow head as a decoration at (1,0) coordinate and at (0,1) 
\draw[decoration={markings, mark=at position 0.5 with {\arrow [ ultra thick] {latex}}},
       postaction={decorate}]
        (0,0)--( 2,0);
\draw[decoration={markings, mark=at position 0.5 with {\arrow [ ultra thick] {stealth}}},
       postaction={decorate}]
        (0,0)--( 0,2);
\end{tikzpicture}
%
\begin{tikzpicture}[scale=1.5,cap=0.5 ,color= blue] 

% grid
\draw[very thin,color = green,step = 0.5 cm, opacity= 0.9](0,0) grid (4, 4);

% axis 
\draw[->]  [blue,  thick] ( 0,0) --( 4,0) node[right] {$x$};
\draw[->]  [blue,  thick] ( 0,0) --( 0,4) node[above] {$y$};
% how to change the arrow tip style at specific path
% how to set up unique arrow head as a decoration at (1,0) coordinate and at (0,1) 
\draw[decoration={markings, mark=at position 0.5 with {\arrow [ ultra thick] {>}}},
       postaction={decorate}]
        (0,0)--( 2,0);
\draw[decoration={markings, mark=at position 0.5 with {\arrow [ ultra thick] {>}}},
       postaction={decorate}]
        (0,0)--( 0,2);
\end{tikzpicture}
\end{document}

Related Solutions

[Tex/LaTex] How to style Tikz arrow tip for state-loop

I have no idea why your example doesn't work, but specifying the arrow tip with ->, >=triangle 60 instead works for me.

\documentclass[a4paper,abstracton,11pt]{scrreprt}
\usepackage{tikz}
\usetikzlibrary{automata}
\usetikzlibrary{arrows}
\begin{document}
\begin{tikzpicture}
\node (loop-node) at (0,0) {node};
\node (path-start) at (2,0) {start};
\node (path-end) at (2,2) {goal};
\path (path-start) edge [-triangle 60] node {path} (path-end)
(loop-node) edge [loop above,->, >=triangle 60] node {edge} ();
\end{tikzpicture}
\end{document}

[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)

Best Answer

Code:

Related Solutions

[Tex/LaTex] How to style Tikz arrow tip for state-loop

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

Related Question