# Drawing Ellipse and Half-Ellipse in LaTeX

how can I draw some ellipses being "cut" by a half-ellipse like in the image (and also being able to write some labels on the ellipses)?

And also, what should I do if I want to have a circle/ellipse within a circle/ellipse (n times) and want to do this "cut" by a half-ellipse? So far, inspired by some answers here, I can only do the following to draw the circles:

\begin{tikzpicture}

\node[circle, minimum size=6cm, draw, fill=white] (a) {};
\node[circle, minimum size=4cm, draw, fill=white] (b) {};
\node[circle, minimum size=2cm, draw, fill=white] (c) {$T_{0}$};

\draw [decorate, decoration={text along path, text = H2}] (150:2.5) arc (150:60:2.5cm);

\draw [decorate, decoration={text along path, text = T1 ~ ~ ~ ~ ~ ~ T2}] (90:1.5) arc (90:-90:1.5cm);

\end{tikzpicture}


Thank you!

This produces something similar to your screen shot.

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{intersections}
\begin{document}
\begin{tikzpicture}
\foreach \Y [count=\Z] in {-1,1}
\draw[red,name path=elli-3] (0,1.9) arc(35:-220:1.6 and 2.4)
node[pos=0.8,left]{$\mathsf{K}*\mathsf{A}$}
(0,1.9) arc(35:40:1.6 and 2.4);
\draw[blue,name path=elli-4] (0,1.9) arc(145:400:1.6 and 2.4) node[pos=0.8,right]{$\mathsf{K}*\mathsf{B}$}
(0,1.9) arc(145:140:1.6 and 2.4);
\path[name intersections={of=elli-1 and elli-3,by={i1,i2,i3,i4}}]  (i4) node[above
right]{$\mathsf{H}_1$};
\path[name intersections={of=elli-3 and elli-4,by={i5,i6}}]  (i6)
node[left]{$\mathsf{T}_1$} node[right,xshift=1ex,yshift=-1ex]{$\mathsf{T}_2$};
\path[name intersections={of=elli-1 and elli-4,by={i7,i8,i9,i10}}]  (i10)
node[below right,xshift=1em]{$\mathsf{K}$};
\end{tikzpicture}
\end{document}


I don't understand the mathematical or logical meaning of your diagram (e.g. does the red ellipse need to be tangent with the black ellipse?), so I can't redraw it accurately. However, the following code draw two full ellipses and one partial ellipse.

\documentclass[tikz]{standalone}
\begin{document}
\begin{tikzpicture}
\draw (0,0) ellipse (2cm and 1cm);
\draw (0,3) ellipse (2cm and 1cm);
\draw (-3,1.5) +(60:1cm and 2cm) arc (60:-240:1cm and 2cm);
\end{tikzpicture}
\end{document}


Now, changing the coordinates, the 1cms and the 2cm, and adding the text is your job. I think you can do it now.

\documentclass[margin=1cm, tikz]{standalone}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}[scale = 2]
% Red half oval
\begin{scope}[shift = {(0,0)}, local bounding box = redScope]
\clip(1,-1)rectangle(-1,0.7);
\end{scope}
\node[red] at (redScope.west) {$\mathsf{K}*\mathsf{A}$};
% Blue half oval
\begin{scope}[shift={(1,0)}, local bounding box = blueScope]
\clip(1,-1)rectangle(-1,0.7);
\end{scope}
\node[blue] at (blueScope.east) {$\mathsf{K}*\mathsf{B}$};
% Upper black oval
\begin{scope}[shift={(0.5,0.25)}]
\node[blue] at (blueScope.east) {$\mathsf{K}*\mathsf{B}$};
\end{scope}
% Lower black oval
\begin{scope}[shift={(0.5,-0.6)}]
\node[black] at (redScope.south)[xshift=-0.5cm,yshift=0.6cm] {$\mathsf{H_1}$};
\node[black] at (redScope.south)[xshift= 0.5cm,yshift=0.6cm] {$\mathsf{T_1}$};
\node[black] at (blueScope.south)[yshift=0.6cm] {$\mathsf{T_2}$};
\node[black] at (blueScope.south east)[xshift=-0.5cm,yshift=0.25cm] {$\mathsf{K}$};