3

We can mark a point on ellipse using

\node[Maroon,draw,fill,circle,inner sep=1pt,label={-90:$X$}] (X) at (-120:2cm and 1cm) {};

Is there any way to define a point on parabola?

\documentclass[border=2pt]{standalone}
\usepackage[usenames,dvipsnames,svgnames]{xcolor}
\usepackage{tikz}

\color{Maroon} 

\begin{document}
\begin{tikzpicture}
\draw[thin,gray!50](-3,-2) grid (3,2);
\draw[Maroon,thick] (0,0) ellipse (2cm and 1cm);
\node[Maroon,draw,fill,circle,inner sep=1pt,label={-90:$X$}] (X) at (-120:2cm and 1cm) {};

\draw[red] (-1,0) parabola[parabola height=1.5cm] (2,0);
\end{tikzpicture}

\end{document}

enter image description here

4
  • Isn't this a duplicate of your own question?
    – Thruston
    Nov 22, 2018 at 10:13
  • @Thruston Using "decoration", i can not define different points on the curve. Here in ellipse, i can define point "X" based on the angle.
    – sandu
    Nov 22, 2018 at 10:18
  • 2
    Why can't you just load decorations.markings and do \draw[red,postaction={decorate,decoration={markings, mark=at position 0.2 with {% \node[red,draw,fill,circle,inner sep=1pt,label={-90:$Y$}](Y){};}}}] (-1,0) parabola[parabola height=1.5cm] (2,0);? Here the position plays the same role as the angle, it parametrizes the position of the location.
    – user121799
    Nov 22, 2018 at 12:45
  • @JouleV Yes....
    – sandu
    Mar 4, 2019 at 3:55

1 Answer 1

1

Based on marmot comment...

\documentclass[border=2pt]{standalone}
\usepackage[usenames,dvipsnames,svgnames]{xcolor}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\color{Maroon} 

\begin{document}
\begin{tikzpicture}
\draw[thin,gray!50](-3,-2) grid (3,2);
\draw[Maroon,thick] (0,0) ellipse (2cm and 1cm);
\node[Maroon,draw,fill,circle,inner sep=1pt,label={-90:$X$}] (X) at (-150:2cm and 1cm) {};

%\draw[red] (-1,0) parabola[parabola height=1.5cm] (2,0);
\draw[red,postaction={decorate,decoration={markings, mark=at position 0.5 with { \node[red,draw,fill,circle,inner sep=1pt,label={-90:$Y$}](Y){};}}}] (-1,0) parabola[parabola height=1.5cm] (2,0);
\end{tikzpicture}

\end{document}

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.