为集合 $X$ 中的元素绘制一个点，命名为 $x$

Question

我正在尝试制作如下的映射图：

 \begin{tikzpicture}
  \tikzset{
      elps/.style 2 args={draw,ellipse,minimum width=#1,minimum height=#2},
      node distance=3 cm,
      font=\footnotesize,
      >=latex, }
   \node(y)[elps={2cm}{3cm},label={below left:$X$}]{};
    \node(v)[elps={2cm}{3cm},right=3 of y,label={below left:$ Y $}]{};
    \node(z)[elps={2cm}{3cm},right=3 of v,label={below right:$Z$}]{};

    \draw[->](y)to[bend left=10] node[below]{$ f $}(v);
    \draw[->](v)to[bend left=10] node[below right]{$ g $}(z);
    \draw[->](y)to[bend right=40]node[below]{$ h $}(z);
   \end{tikzpicture}

现在我想从 $X$ 中指出一个元素 $x$，然后在 $Y$ 中指出 $f(x)$。那么我如何在 $X$ 中画一个点，命名为 $x$。谢谢。

Answer 1

例如，附加一个项目符号样式：

\documentclass[border=10pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes,positioning}
\begin{document}
\begin{tikzpicture}
  \tikzset{
      elps/.style 2 args={draw, ellipse,minimum width=#1, minimum height=#2},
      node distance=3 cm,
      font=\footnotesize,
      >=latex,
% Add this style:
     bullet/.style = {circle, inner sep=1pt, fill}}
    \node(y)[elps={2cm}{3cm}, label={below left:$X$}]{};
    \node(v)[elps={2cm}{3cm}, right=3 of y,label={below left:$ Y $}]{};
    \node(z)[elps={2cm}{3cm}, right=3 of v,label={below right:$Z$}]{};

    \draw[->](y)to[bend left=10] node[below]{$ f $}(v);
    \draw[->](v)to[bend left=10] node[below right]{$ g $}(z);
    \draw[->](y)to[bend right=40]node[below]{$ h $}(z);
% Add:
    \node (element) [circle, inner sep = 1pt, fill,
      below left = -0.5cm and -1 cm of y, label = {below right:$x$}] {};
    \node (element) [bullet, below left = -0.5cm and -1 cm of y,
      label = {below right:$x$}] {};
    \node (value) [bullet, above left = -0.5cm and -1 cm of v,
      label = {below right:$f(x)$}] {};
    \draw[->, dashed] (element)  to[bend right=20] (value);
   \end{tikzpicture}
\end{document}