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编辑

有人有“角弹簧”的宏吗？我在 (PS-Tricks 包) 中寻找类似的东西，pst-coil但“弹簧”的几何形状不是直线而是拱形（最终具有可变开口）。

答案1

运行lualatex：

\documentclass{article} 
\usepackage{luamplib}
\begin{document}
\begin{mplibcode}
input metaobj
beginfig(1);
  newCircle.a(btex start etex);
  newCircle.b(btex end etex);
  a.c=origin;
  b.c-a.c=(3cm,2cm);
  drawObj(a,b);
  nccoil(a)(b) "coilwidth(3mm)", "linetension(0.8)",
               "angleA(-20)", "angleB(90)", "arrows(-)","linewidth(1pt)";
endfig;

clearObj a,b;
beginfig(2);
  newCircle.a(btex start etex);
  newCircle.b(btex end etex);
  a.c=(0cm,3cm);
  b.c=(5cm,4cm);
  drawObj(a,b);
  nccoil(a)(b) "doubleline(true)","coilwidth(3mm)","linetension(0.8)",
               "angleA(-90)", "angleB(90)", "arrows(-)","linewidth(1pt)";
endfig;
\end{mplibcode}
\end{document}

在此处输入图片描述

答案2

解决这个问题的另一种pstricks方法是通过使用pst-solides3d和滥用螺旋本身。

%&pdflatex
% !TeX TXS-program:compile = txs:///pdflatex/[--shell-escape]
\documentclass[a4paper, pdf, x11names]{standalone}
\usepackage{pstricks}
\usepackage{pstricks-add, auto-pst-pdf}
\usepackage{pst-solides3d}
\begin{document}
    \begin{pspicture}[solidmemory](-6.5,-3.5)(6.5,3)
    \psset{viewpoint=30 0 15 rtp2xyz,Decran=30,lightsrc=viewpoint}
    \pstVerb{/R1 5 def /R0 2 def /k 20 def /RL 0.15 def /kRL 40 def}%
    %https://tex.stackexchange.com/questions/151108/showcase-of-translations-to-asymptote-from-tikz-pstricks
    % abusing the helix to create a sprial spring-like structure
    \defFunction[algebraic]{helix}(t)
    {(R1+R0*cos(k*t))*sin(t)+RL*sin(kRL*k*t)}
    {(R1+R0*cos(k*t))*cos(t)+RL*cos(kRL*k*t)}
    {R0*sin(k*t)+RL*sin(kRL*k*t)}
    \psSolid[object=courbe,
    resolution=7800,
    fillcolor=white,incolor=black,
    r=0,
    range=-0.099 0,
    function=helix,action=none,name=Helix]%
    \psSolid[object=fusion,base=Helix]
    % start-stop circles
    \pscircle(4,-1.25){0.3}
    \pscircle(7.1,0.3){0.3}
    % texts
    \rput[c](4,-1.25){\tiny Stop}
    \rput[c](7.1,0.3){\tiny Start}
    %\put(-1,-3){$\text{multiples of 6}$}
    \end{pspicture}
\end{document}

这将给你：

在此处输入图片描述

在这里，你可以使用以下参数

\pstVerb{/R1 5 def /R0 2 def /k 20 def /RL 0.15 def /kRL 40 def}%

以获得更多奇特的变化。

答案3

为了简单起见，末端的琐碎球被故意删除。

\documentclass[pstricks,border=1cm]{standalone}
\usepackage{pst-plot}
\newcommand\circularSpring[4][]{%
    \curvepnodes[plotpoints=\numexpr#4*4+1]{#2 DegtoRad}{#3 DegtoRad}
        {(sin(#4*t)/5+2)*cos(t)|(sin(#4*t)/5+2)*sin(t)}{A}
    \psnline[linejoin=1,#1](0,\Anodecount){A}}


\begin{document}
\begin{pspicture}[showgrid](-3,-3)(3,3)
    \pscircle[linecolor=red,linestyle=dashed]{2}
    \circularSpring{45}{90}{100}
    \circularSpring{0}{-90}{200}
\end{pspicture}
\end{document}

在此处输入图片描述

编辑

几乎被遗忘的动画。

\documentclass[pstricks]{standalone}
\usepackage{pst-plot}
\newcommand\circularSpring[4][]{%
    \curvepnodes[plotpoints=\numexpr#4*4+1]{#2 DegtoRad}{#3 DegtoRad}
        {(sin(#4*t)/5+2)*cos(t)|(sin(#4*t)/5+2)*sin(t)}{A}
    \psnline[linejoin=1,#1](0,\Anodecount){A}}


\begin{document}
\multido{\i=0+36}{11}{%
\begin{pspicture}(-3,-3)(3,3)
    \pscircle[linecolor=red,linestyle=dashed]{2}
    \circularSpring{0}{\i}{50}
\end{pspicture}}
\end{document}

在此处输入图片描述

注意：由于错误采样点而导致的练习中会出现一些小故障。

答案4

SkiaSharp 解决方案仅用于比较目的。它也可以嵌入 LaTeX 方程式。

using SkiaSharp;
using System.Diagnostics;
using static System.MathF;

class Diagram
{
    const float scale = SKDocument.DefaultRasterDpi / 2.54f; // dots per cm

    static float PtToCm(float pt) => pt / scale;

    static readonly SKPaint blackStrokePaint = new SKPaint
    {
        Style = SKPaintStyle.Stroke,
        StrokeWidth = PtToCm(0.8f),
        Color = SKColors.Black,
        StrokeCap = SKStrokeCap.Round,
        IsAntialias = true
    };

    static readonly SKPaint redStrokePaint = new SKPaint
    {
        Style = SKPaintStyle.Stroke,
        StrokeWidth = PtToCm(0.8f),
        Color = SKColors.Red,
        StrokeCap = SKStrokeCap.Round,
        IsAntialias = true
    };

    static readonly SKRect domain = new SKRect(-2.5f, 2.5f, 2.5f, -2.5f);

    static readonly float width = domain.Width * scale;
    static readonly float height = -domain.Height * scale;

    static readonly int k = 50; // wave number
    static readonly int plotPoints = 4 * k + 1;
    static readonly float dt = PI * 2 / (plotPoints - 1);

    private static SKPoint GetPoint(int index)
    {
        float t = index * dt;
        return new SKPoint
            (
                (Sin(k * t) / 5 + 2) * Cos(t),
                (Sin(k * t) / 5 + 2) * Sin(t)
            );
    }

    public static void Generate(string filename)
    {
        using (var stream = new SKFileWStream($"{filename}.pdf"))
        using (var document = SKDocument.CreatePdf(stream))
        using (var canvas = document.BeginPage(width, height))
        {
            canvas.Scale(scale, -scale);
            canvas.Translate(-domain.Left, -domain.Top);

            canvas.DrawCircle(0, 0, 2, redStrokePaint);

            for (int i = 0; i < plotPoints - 1; i++)
                canvas.DrawLine(GetPoint(i), GetPoint(i + 1), blackStrokePaint);

            document.EndPage();
        }
    }
}

class Invoker
{
    static void Main()
    {
        string filename = "CircularSpring";
        Diagram.Generate(filename);

        // convert to PNG with ImageMagick
        using (Process p = new Process())
        {
            p.StartInfo.FileName = "magick";
            p.StartInfo.Arguments = $"convert -compose copy -bordercolor red -border 2x2 -density 200 -alpha remove {filename}.pdf {filename}.png";
            p.Start();
            p.WaitForExit();
        }
    }
}

在此处输入图片描述

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