使用 TIkZ 进行简单绘图

Question

我想知道是否有人知道如何制作右边的图表。我只知道如何制作非常简单的图表。

有没有办法将阴影球和图形放在同一个图中？

Answer 1

在图书馆的帮助下intersections：

\documentclass[border=3.141592]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}
\usetikzlibrary{intersections}

\begin{document}
    \begin{tikzpicture}[
dot/.style = {circle, draw, solid, fill=gray, inner sep=1.6pt,
              node contents={}},
                        ]
\begin{axis}[name=plot1,
declare function = {f(\x)=0.5*(x-2)^3-0.2*x+2;},% actual function is unknown
    axis lines = left,
    xlabel={$x$}, ylabel={$\phi_l(x)$},
    xtick=\empty, 
    xmin=0, xmax=4.2,
    ymin=0, 
    restrict y to domain=0:4.4,
    no marks, samples=1000, domain=0:4,
every axis plot post/.append style={very thick},
    clip=false
            ]
\addplot+[thick,name path=P]{f(x)};
%
\path[name path=A]  (0,1) -- (4,1);
\path[name path=B]  (0,2) -- (4,2);
\path[name path=C]  (0,3) -- (4,3);
\path[name path=D]  (0,4) -- (4,4);
%
\path[name intersections={of = P and A, by=x1}];
\path[name intersections={of = P and B, by=x2}];
\path[name intersections={of = P and C, by=x3}];
\path[name intersections={of = P and D, by=x4}];
%
\draw[densely dashed, very thin] 
    (0,1) -| (x1 |- 0,0) node[dot] 
    (0,2) -| (x2 |- 0,0) node[dot]
    (0,3) -| (x3 |- 0,0) node[dot]
    (0,4) -| (x4 |- 0,0) node[dot];
\end{axis}
    \end{tikzpicture}
\end{document}

如果您喜欢带阴影的点节点，则需要将dot样式修改为：

dot/.style = {circle, draw, solid, semithick,
              left color=gray!10, right color=gray!90, inner sep=1.6pt,
              node contents={}},

在这种情况下，图表如下：