How to draw a set with a letter or number inside?

Question

I want to draw a set like this:

but don't know how to do it. I mean, how to put an object inside the set.

Look at the questions here: [tag:venn-diagrams] and then ask a question with example code that you're having trouble with. — Alan Munn, Feb 16 '18 at 15:46
@Zarko But I don't know how to draw Venn diagram. I know how to type formulas and so on. I read the question below, but it is about more than one set. https://tex.stackexchange.com/questions/9681/how-to-draw-venn-diagrams-especially-complements-in-latex — spohreis, Feb 16 '18 at 15:49
@spohreis -- Something as simple as \begin{tikzpicture} \node [circle, draw, minimum size=2cm] {A}; \end{tikzpicture} would do the job. — AboAmmar, Feb 16 '18 at 15:53
copy this answer to your computer and start to experimenting. make some small changes and look what will happen. code is fairly self explanatory. also help read documentation of packages. in link case tikz & pgf manual. it is huge, however for start is sufficient to read tutorials and part three. maybe meanwhile some good soul, which offer service "i will-do-this-instead-you" provide you desired. — Zarko, Feb 16 '18 at 15:55

Zarko · Answer 1 · 2018-02-16T23:24:55.293

using neerby answer (+1) as starting point ... the slightly shortened code can be:

\documentclass[tikz, margin=5mm]{standalone}

\begin{document}
    \begin{tikzpicture}[
ven/.style = {fill=#1, fill opacity=0.5},   % common style for ellipses
every node/.append style ={text opacity=1}  % set text opacity for all nodes
                        ]
\draw[ven=orange]   (0,4)   % coordinate of the ellipse center
                            ellipse (1 and .6) % size of ellipse defined by its radius
                                               node {A}; % node with text in ellipse, 
                                                         % positioned at ellipse center
\draw[ven=cyan]     (3,3.5) ellipse (1 and .6) node {B};
\draw[ven=green]    (0,0)   ellipse (1 and .6) node {C};
\draw[ven=red]      (3,0)   ellipse (1 and .6) node {D};
\draw[ven=yellow]   (4.5,0) ellipse (1 and .6) node {E};
    \end{tikzpicture}
\end{document}

edit: consider kpym suggestion in comment below, the above code can be even shorter. instead of drawing ellipse, you shape ellipse defined in tikz˙libraryshapes.gometric`:

\documentclass[tikz, margin=5mm]{standalone}
\usetikzlibrary{shapes.geometric}

\begin{document}
    \begin{tikzpicture}[
ven/.style = {ellipse, draw, fill=#1, fill opacity=0.5, text opacity=1,
              minimum width =21mm, minimum height=13mm, },  % common style for ellipses
                        ]
\node[ven=orange]   at (0,3)    {A};
\node[ven=cyan]     at (3,3.5)  {B};
\node[ven=green]    at (0,0)    {C};
\node[ven=red]      at (3,0)    {D};
\node[ven=yellow]   at (4.5,0)  {E};
    \end{tikzpicture}
\end{document}

the result is the same as before:

It is probably shorter to define ven/.style = {draw=#1,fill=#1, fill opacity=0.5,text opacity=1,ellipse,minimum height=2em,minimum width=4em} and then to use node[ven=cyan]{A} directly. — Kpym, Feb 16 '18 at 22:57
@Kpym, you have right. apparently dinner disturb me in writing of answer :-). can i add your suggestion to my answer or you intend to write own? — Zarko, Feb 16 '18 at 23:03
Note : if you want a code without shapes.geometric you can define the styles like this ellipse label/.style={circle, yscale=13/21,draw, fill opacity=0.5,fill=#1, minimum size=21mm,behind path} and ven/.style ={label={[ellipse label=#1]center:}} — Kpym, Feb 17 '18 at 07:48

score 4 · Answer 2 · answered Feb 16 '18 at 18:11

\documentclass{standalone}
\usepackage{tikz}
\begin{document}
    \begin{tikzpicture}[scale=.5]
        \def\OPAC{.5}
        \draw[fill=orange, fill opacity=\OPAC] (0,0) ellipse (1.5 and 1) node[opacity=1] {A};
        \draw[fill=cyan, fill opacity=\OPAC] (6,-.5) ellipse (1.5 and 1) node[opacity=1] {B};
        \draw[fill=green, fill opacity=\OPAC] (0,-4) ellipse (1.5 and 1) node[opacity=1] {C};
        \draw[fill=red, fill opacity=\OPAC] (5,-4.5) ellipse (1.5 and 1) node[opacity=1] {D};
        \draw[fill=yellow, fill opacity=\OPAC] (7,-4.5) ellipse (1.5 and 1) node[opacity=1] {E};
    \end{tikzpicture}
\end{document}

Franck Pastor · Answer 3 · 2018-02-16T23:36:17.280

Just for fun, the same picture with MetaPost, with the same coordinates as in the previous answers, and with help from the Metafun format for the transparency. Code included in a LuaLaTeX program.

\RequirePackage{luatex85}
\documentclass[border=5mm]{standalone}
\usepackage{luamplib}
    \mplibsetformat{metafun}
\begin{document}
\begin{mplibcode}
path ellipse[];
pair C[]; C1 = (0, 4cm); C2 = cm*(3, 3.5); C3 = origin; C4 = (3cm, 0); C5 = (4.5cm, 0);
color c[]; c1 = .5[red,yellow]; c2 = cyan; c3 = green; c4 = red; c5 = yellow;
beginfig(1);
    for i = 1 upto 5:
        ellipse[i] = fullcircle xscaled 2cm yscaled 1.2cm shifted C[i];
        fill ellipse[i] withcolor c[i] withtransparency ("normal", .5); draw ellipse[i]; 
        label(textext(char(64+i)), C[i]);
    endfor;
endfig;
\end{mplibcode}
\end{document}

How to draw a set with a letter or number inside?

3 Answers3