如何修改给定的代码以便在给定的输出上绘制 p1 之前和 p3 之后的交叉路径和箭头

Question 1

我很幸运地找到了一些如何做到这一点的例子，我发现这很有趣。在代码中，你可以找到前面示例的链接。

结果：

梅威瑟：

\documentclass[tikz,border=0.5cm]{standalone}
\usetikzlibrary{decorations.pathmorphing,decorations.markings,intersections}

%this code is from Guilherme Zanotelli  in a "short" explanation in https://tex.stackexchange.com/a/333824/154390 [start]
\newcommand\bonusspiral{} % just for safety
% \bonusspiral[draw options](placement)(start angle:end angle)(start radius:final radius)[revolutions]
\def\bonusspiral[#1](#2)(#3:#4)(#5:#6)[#7]{
    \pgfmathsetmacro{\domain}{#4+#7*360}
    \pgfmathsetmacro{\growth}{180*(#6-#5)/(pi*(\domain-#3))}
    \draw [#1,
    shift={(#2)},
    domain=#3*pi/180:\domain*pi/180,
    variable=\t,
    name path=plotA,
    %smooth,
    samples=int(\domain/5)] plot ({\t r}: {#5+\growth*\t-\growth*#3*pi/180});
}

%this code is from Frunobulax https://tex.stackexchange.com/a/445690/154390
\makeatletter
\pgfset{
    /pgf/decoration/randomness/.initial=2,
    /pgf/decoration/wavelength/.initial=100
}
\pgfdeclaredecoration{sketch}{init}{
    \state{init}[width=0pt,next state=draw,persistent precomputation={
        \pgfmathsetmacro\pgf@lib@dec@sketch@t0
    }]{}
    \state{draw}[width=\pgfdecorationsegmentlength,
    auto corner on length=\pgfdecorationsegmentlength,
    persistent precomputation={
        \pgfmathsetmacro\pgf@lib@dec@sketch@t{mod(\pgf@lib@dec@sketch@t+pow(\pgfkeysvalueof{/pgf/decoration/randomness},rand),\pgfkeysvalueof{/pgf/decoration/wavelength})}
    }]{
        \pgfmathparse{sin(2*\pgf@lib@dec@sketch@t*pi/\pgfkeysvalueof{/pgf/decoration/wavelength} r)}
        \pgfpathlineto{\pgfqpoint{\pgfdecorationsegmentlength}{\pgfmathresult\pgfdecorationsegmentamplitude}}
    }
    \state{final}{}
}
\tikzset{pencildraw/.style={decorate,decoration={sketch,segment length=1pt,amplitude=2pt}}}
\makeatother

\begin{document}
    \begin{tikzpicture}[
        Ina/.style={
            draw,
            postaction={
                decorate,
                decoration={
                    markings,
                    mark=at position #1 with {
                        \fill[xscale=-1,xshift=-1pt](0:6pt) -- (90+50:4pt) -- (180:2pt) -- (270-50:4pt);
                    }
                }
            }
        }
    ]
    %Start drawing the thing.
    % First spiral that starst from 15 at radious 1 and ends at 120 at radious 3 in two revolutions.
    \bonusspiral[thick,yscale=0.7,pencildraw,Ina=0.97,postaction={Ina=0}](0,0)(15:120)(1:3)[2]  
    \draw[thick,Ina=0,name path=plotB](0,0.2) to [out=100,in=-100] ++ (0,2.5) node[anchor=0]{S};
    \fill [name intersections={of=plotA and plotB, name=E, total=\t}][black]
    \foreach \s in {1,2,...,\t}{(E-\s) circle (2pt) node[inner sep=0,label={[label distance=-0.2em]45:$\rho_\s$}]{}};       
    \end{tikzpicture} 
\end{document}

附录：

为了反转枚举，我使用了一个额外的计数器并更改了计数器的顺序。\foreach \s [count=\ss from 1]in {\t,...,2,1}请记住，在调整螺旋时，它是从内向外绘制的，因此箭头用反转xscale=-1，并使用移位，以便在适应曲线时具有更好的效果。代码允许您使用更多节点扩展结果，这一切都归功于\bonusspiral宏

新结果：

新 MWE：

\documentclass[tikz,border=0.5cm]{standalone}
\usetikzlibrary{decorations.pathmorphing,decorations.markings,intersections}

%this code is from Guilherme Zanotelli  in a "short" explanation in https://tex.stackexchange.com/a/333824/154390 [start]
\newcommand\bonusspiral{} % just for safety
% \bonusspiral[draw options](placement)(start angle:end angle)(start radius:final radius)[revolutions]
\def\bonusspiral[#1](#2)(#3:#4)(#5:#6)[#7]{
    \pgfmathsetmacro{\domain}{#4+#7*360}
    \pgfmathsetmacro{\growth}{180*(#6-#5)/(pi*(\domain-#3))}
    \draw [#1,
    shift={(#2)},
    domain=#3*pi/180:\domain*pi/180,
    variable=\t,
    name path=plotA,
    %smooth,
    samples=int(\domain/5)] plot ({\t r}: {#5+\growth*\t-\growth*#3*pi/180});
}

%this code is from Frunobulax https://tex.stackexchange.com/a/445690/154390
\makeatletter
\pgfset{
    /pgf/decoration/randomness/.initial=2,
    /pgf/decoration/wavelength/.initial=100
}
\pgfdeclaredecoration{sketch}{init}{
    \state{init}[width=0pt,next state=draw,persistent precomputation={
        \pgfmathsetmacro\pgf@lib@dec@sketch@t0
    }]{}
    \state{draw}[width=\pgfdecorationsegmentlength,
    auto corner on length=\pgfdecorationsegmentlength,
    persistent precomputation={
        \pgfmathsetmacro\pgf@lib@dec@sketch@t{mod(\pgf@lib@dec@sketch@t+pow(\pgfkeysvalueof{/pgf/decoration/randomness},rand),\pgfkeysvalueof{/pgf/decoration/wavelength})}
    }]{
        \pgfmathparse{sin(2*\pgf@lib@dec@sketch@t*pi/\pgfkeysvalueof{/pgf/decoration/wavelength} r)}
        \pgfpathlineto{\pgfqpoint{\pgfdecorationsegmentlength}{\pgfmathresult\pgfdecorationsegmentamplitude}}
    }
    \state{final}{}
}
\tikzset{pencildraw/.style={decorate,decoration={sketch,segment length=1pt,amplitude=2pt}}}
\makeatother

\begin{document}
    \begin{tikzpicture}[
        Ina/.style={
            draw,
            postaction={
                decorate,
                decoration={
                    markings,
                    mark=at position #1 with {
                        \fill[xscale=-1,xshift=-1pt](0:6pt) -- (90+50:4pt) -- (180:2pt) -- (270-50:4pt);
                    }
                }
            }
        }
    ]
    %Start drawing the thing.
    % First spiral is used as workspace a spiral that starts from 90 at radious 1 and ends at 90 at radious 6.
    \bonusspiral[thick,yscale=0.7,pencildraw,Ina=0.98,postaction={Ina=0}](0,0)(15:120)(1:5)[4]  
    \draw[thick,Ina=0,name path=plotB](0,0.2) to [out=100,in=-100] ++ (0,4) node[anchor=0]{S};
    \fill [name intersections={of=plotA and plotB, name=E, total=\t}][black]
    \foreach \s [count=\ss from 1]in {\t,...,2,1}{(E-\ss) circle (2pt) node[inner sep=0,label={[label distance=-0.2em]45:$\rho_\s$}]{}};        
    \end{tikzpicture} 
\end{document}

Answer