两个正弦波的 tikz 图，显示相位差

Question

我在这里试图实现的是绘制两个正弦波，并在峰值上画一些虚线，中间显示 \Delta t，作为相位差。任何帮助都值得感激。

Answer 1

和pgfplots：

\documentclass{standalone}

\usepackage{pgfplots}
\pgfplotsset{compat=1.11}

\begin{document}
\begin{tikzpicture}
  \begin{axis}[
    trig format plots=rad,
    axis lines = middle,
    enlargelimits,
    clip=false
    ]
    \addplot[domain=-2*pi:2*pi,samples=200,blue] {sin(x)};
    \addplot[domain=-2*pi:2*pi,samples=200,red] {sin(x-2)};
    \draw[dotted,blue!40] (axis cs: 0.5*pi,1.1) -- (axis cs: 0.5*pi,0);
    \draw[dotted,red!40] (axis cs: 0.5*pi+2,1.1) -- (axis cs: 0.5*pi+2,0);
    \draw[dashed,olive,<->] (axis cs: 0.5*pi,1.05) -- node[above,text=black,font=\footnotesize]{$\Delta t$}(axis cs: 0.5*pi+2,1.05);
  \end{axis}
\end{tikzpicture}
\end{document}

Answer 2

\documentclass[tikz]{standalone}

\begin{document}
\begin{tikzpicture}[xscale=3,yscale=2]
  \draw[<->] (0,-1.3) -- (0,1.3);
  \draw[->] (0,0)--(4.3,0);
  \draw[domain=0:4.3,samples=100,blue] plot(\x,{sin(\x r)});
  \draw[domain=0:4.3,samples=100,red] plot(\x,{sin((\x-1) r)});
  \draw[dashed] (pi/2,0) -- (pi/2,1.3);
  \draw[dashed] (pi/2+1,0) -- (pi/2+1,1.3);
  \draw[<->] (pi/2,1.15) -- node[above]{\small $\Delta t$} (pi/2+1,1.15);
\end{tikzpicture}
\end{document}

Answer 3

使用 PSTricks 的解决方案只是为了好玩。由于设置没有捆绑为新包，因此故意做得很冗长。很抱歉给您带来不便，感谢您的合作。

\documentclass[pstricks,12pt,dvipsnames]{standalone}
\usepackage{amsmath}
\usepackage{pstricks-add}
\usepackage{pst-plot}

\usepackage[nomessages]{fp}

\FPeval\XMin{0-pi/6}
\FPeval\XMax{2*pi}
\FPeval\YMin{0-3/2}
\FPeval\YMax{5/2}

\FPeval\XOL{0-1/2} % of DeltaX
\FPeval\XOR{1/2} % of DeltaX
\FPeval\YOB{0-1/5} % of DeltaY
\FPeval\YOT{1/5} % of DeltaY

\FPset\xTrigLabelBase{6}
\FPeval\yTrigLabelBase{pi}
\FPset\Dx{1}
\FPset\Dy{1}

\FPeval\dx{pi/xTrigLabelBase*Dx}
\FPeval\dy{pi/yTrigLabelBase*Dy}

\FPeval\AxisL{XMin+dx*XOL}
\FPeval\AxisR{XMax+dx*XOR}
\FPeval\AxisB{YMin+dy*YOB}
\FPeval\AxisT{YMax+dy*YOT}


\newlength\Width\Width=12cm
\newlength\Height\Height=8cm

\newlength\llx\llx=-5pt
\newlength\urx\urx=15pt
\newlength\lly\lly=-5pt
\newlength\ury\ury=15pt


\psset
{
    llx=\llx,
    lly=\lly,
    urx=\urx,
    ury=\ury,
    xtrigLabels=true,
    %ytrigLabels=true,
    xtrigLabelBase=\xTrigLabelBase,
    %ytrigLabelBase=\yTrigLabelBase,
    labelFontSize=\scriptstyle,
    xAxisLabel=$x$,
    yAxisLabel=$y$,
    algebraic,
    plotpoints=500,
}

\newpsstyle{mygrid}
{
        dx=\dx,
        dy=\dy,
        %Dx=\Dx,
        %Dy=\Dy,
        labels=none,
        subticks=5,
        tickwidth=.4pt,
        subtickwidth=.2pt,
        tickcolor=Red!30,
        subtickcolor=ForestGreen!30,
        xticksize=\YMin\space \YMax,
        yticksize=\XMin\space \XMax,
        subticksize=1,
}

\def\f{sin(x)}
\def\g{sin(x+Pi/6)}


\begin{document}
\pslegend[rt]{%
    \color{NavyBlue}\rule{12pt}{1pt} & \color{NavyBlue} $y=\sin x$ \\
    \color{Red}\rule{12pt}{1pt} & \color{Red} $y=\sin(x+\pi/6) x$ 
}
\begin{psgraph}
    [
        dx=\dx,
        dy=\dy,
        Dx=\Dx,
        Dy=\Dy,
        linecolor=gray,
        tickcolor=gray,
        ticksize=-3pt 3pt,
        axespos=top,
    ]{<->}(0,0)(\AxisL,\AxisB)(\AxisR,\AxisT){\dimexpr\Width-\urx+\llx}{!}%{\dimexpr\Height-\ury+\lly}
    \psaxes[style=mygrid](0,0)(\XMin,\YMin)(\XMax,\YMax)
    \psplot[linecolor=NavyBlue]{\XMin}{\XMax}{\f}
    \psplot[linecolor=Red]{\XMin}{\XMax}{\g}
    \pcline[linestyle=dashed,offset=.5,linecolor=Magenta]{|*-|*}(*{Pi 3 div} {\f})(*{Pi 2 div} {\g})\naput{ $\scriptstyle\Delta x = \tfrac{\pi}{6}$}
\end{psgraph}
\end{document}

突出特点：

1. 横轴可以是小数，也可以是π的分数倍。
2. 背景网格使我们能够以更高的精度定位（读取）图表上的任意点。
3. ETC。