填充椭圆区域

Question

我可以使用以下代码轻松绘制椭圆：

\documentclass[tikz, margin=5pt]{standalone}
\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,
     bullet/.style = {circle, inner sep=1pt, fill}}

     \node(a)[elps={2cm}{3cm}, label={below:$A$}]{};

   \end{tikzpicture}
\end{document}

怎样才能在不完全改变（如果可能的话）我的实际代码的情况下实现如图所示的结果？

Answer 1

以下是使用的建议path picture：

\documentclass[margin=5pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{shapes,positioning}

  \newcommand\ppfill[2]{%
    \foreach \c/\dir in {#1/{north },#2/{south }}
      \path[fill=\c,draw]
        (path picture bounding box.\dir west)--
        (path picture bounding box.west)to[out=-60,in=210]
        (path picture bounding box.center)to[out=30,in=120]
        (path picture bounding box.east)--
        (path picture bounding box.\dir east)--cycle
      ;
  }

\begin{document}
\begin{tikzpicture}
  \tikzset{
    elps/.style 2 args={draw, ellipse,minimum width=#1, minimum height=#2},
    node distance=3 cm,
    font=\footnotesize,
    >=latex,
    bullet/.style = {circle, inner sep=1pt, fill}
  }

     \node(a)[elps={2cm}{3cm},label={below:$A$}]
        [path picture=\ppfill{red}{green}]{};

     \node(b)[elps={5cm}{3cm},label={below:$B$}]
        [right=1cm of a,draw=orange,line width=1mm]
        [path picture=\ppfill{green}{blue}]{};

   \end{tikzpicture}
\end{document}

结果：