[Tex/LaTex] Drawing arrows along a function in pgfplots

tikz-pgf

How does one insert arbitary placed arrows along a curve/function
defined in pgfplots using the \plot command. I realise the last sentence became a tad long.. Below is a simple code for which I am trying to insert arrows, if I had
points to go after, I could have used something like Pgfplots: Drawing Arrows Along Contour Plots
or decorations. But this does not work here…

Earlier i asked the same question with the draw function Add arrows to a smooth tikz function, and obtained a really good answer.
However implementing the solution directly to the code under gives missfortunate 'stack overflow' error. To summarize

Is there a way to place a number of arrows a long a function / curve made with pgfplots?

Presumably with a similar syntax to

\draw plot ... [arrow inside={end=stealth,opt={scale=2}}{0.25,0.5,0.75}];

Here is one figure I am trying to add a few arrows too

\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\tikzset{
    set arrow inside/.code={\pgfqkeys{/tikz/arrow inside}{#1}},
    set arrow inside={end/.initial=>, opt/.initial=},
    /pgf/decoration/Mark/.style={
        mark/.expanded=at position #1 with
        {
            \noexpand\arrow[\pgfkeysvalueof{/tikz/arrow inside/opt}]{\pgfkeysvalueof{/tikz/arrow inside/end}}
        }
    },
    arrow inside/.style 2 args={
        set arrow inside={#1},
        postaction={
            decorate,decoration={
                markings,Mark/.list={#2}
            }
        }
    },
}
\begin{document}
\begin{tikzpicture}
\draw node [circle] at (-1,0) {$z_0$};
\begin{scope}[very thick,rotate=45,decoration={
    markings,
    mark=at position 0.5 with {\arrow{>}}}]
\draw[domain=0:6.28,samples=200,smooth,] plot (xy polar
cs:angle=\x r,radius=      {1-sin(2*\x r)}) ;
\end{scope}
\end{tikzpicture} 
\end{document}

Lemniscate

Best Answer

As you didn't answer my comment yet, I will just post my solution to the problem I think you are trying to solve.

You may just use the code, given in my answer to this question: Add arrows to a smooth tikz function Next you will need to remove the smooth statement, because it will interfere with decorate and give you nice errors like ? Dimension too large. This won't have an effect on the smoothness of your drawing, because you already use sufficiently many samples.

Implementation

\documentclass[border=5pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\tikzset{
  set arrow inside/.code={\pgfqkeys{/tikz/arrow inside}{#1}},
  set arrow inside={end/.initial=>, opt/.initial=},
  /pgf/decoration/Mark/.style={
    mark/.expanded=at position #1 with
    {
      \noexpand\arrow[\pgfkeysvalueof{/tikz/arrow inside/opt}]{\pgfkeysvalueof{/tikz/arrow inside/end}}
    }
  },
  arrow inside/.style 2 args={
    set arrow inside={#1},
    postaction={
      decorate,decoration={
        markings,Mark/.list={#2}
      }
    }
  },
}
\begin{document}
\begin{tikzpicture}
  \draw node [circle] at (-1,0) {$z_0$};
  \begin{scope}[very thick,rotate=45]
    \draw[domain=0:6.28,samples=200] plot (xy polar cs:angle=\x r,radius={1-sin(2*\x r)}) [arrow inside={}{0.25,0.5,0.75}];
  \end{scope}
\end{tikzpicture} 
\end{document}

Output

Related Solutions

[Tex/LaTex] Shortcut for arrows on curves in TikZ

Macros in style definitions don't work if they aren't expanded beforehand. You should define your own style instead.

\tikzset{arrow data/.style 2 args={%
      decoration={%
         markings,
         mark=at position #1 with \arrow{#2}},
         postaction=decorate}
      }%
}

The use it like:

\draw [arrow data={0.3}{>}] (A) to (B);

[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)