有没有更好的方法来绘制这个 TikZ 图？

Question

我是 TikZ 的绝对初学者。我试图绘制一段时间内的图表。阅读了这里的几篇文章和 Overleaf 上的一些教程后，我想到了这一点：

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{math}
\usetikzlibrary{calc}

\tikzmath
{
 \vmax1 = 0.25;
 \vmax2 = 0.125;
 \vmax3 = -\vmax1;
 \t1    = 0.5;
 \t2    = 2.1999995;
 \t3    = \t1;
 \t4    = \t1;
 \t5    = 4.3999995;
 \t6    = \t1;
 \t7    = \t1;
 \t8    = 4.3999995;
 \t9    = \t1;
}
\begin{document}
 \begin{tikzpicture}
  \draw[yscale=10, very thick]
   (0, 0) --
   ($ (0, 0) +(\t1, \vmax1) $) --
   ($ (0, 0) +(\t1, \vmax1) +(\t2, 0) $) --
   ($ (0, 0) +(\t1, \vmax1) +(\t2, 0) +(\t3, -\vmax1) $) --
   ($ (0, 0) +(\t1, \vmax1) +(\t2, 0) +(\t3, -\vmax1) +(\t4, \vmax2) $) --
   ($ (0, 0) +(\t1, \vmax1) +(\t2, 0) +(\t3, -\vmax1) +(\t4, \vmax2) +(\t5, 0) $) --
   ($ (0, 0) +(\t1, \vmax1) +(\t2, 0) +(\t3, -\vmax1) +(\t4, \vmax2) +(\t5, 0) +(\t6, -\vmax2) $) --
   ($ (0, 0) +(\t1, \vmax1) +(\t2, 0) +(\t3, -\vmax1) +(\t4, \vmax2) +(\t5, 0) +(\t6, -\vmax2) +(\t7, \vmax3) $) --
   ($ (0, 0) +(\t1, \vmax1) +(\t2, 0) +(\t3, -\vmax1) +(\t4, \vmax2) +(\t5, 0) +(\t6, -\vmax2) +(\t7, \vmax3) +(\t8, 0) $) --
   ($ (0, 0) +(\t1, \vmax1) +(\t2, 0) +(\t3, -\vmax1) +(\t4, \vmax2) +(\t5, 0) +(\t6, -\vmax2) +(\t7, \vmax3) +(\t8, 0) +(\t9, -\vmax3) $)
  ;
 \end{tikzpicture}
\end{document}

从代码角度来看，这确实让人感觉很卡顿。没有更好的方法吗？

Answer 1

\documentclass[tikz, border=1cm]{standalone}
\begin{document}
\begin{tikzpicture}[
declare function={
vmax1 = 0.25;
vmax2 = 0.125;
vmax3 = -vmax1;
t1    = 0.5;
t2    = 2.1999995;
t3    = t1;
t4    = t1;
t5    = 4.3999995;
t6    = t1;
t7    = t1;
t8    = 4.3999995;
t9    = t1;
}]
\draw[yscale=10, very thick] 
  (0,0) -- ++(t1, vmax1) -- ++(t2, 0) -- ++(t3, -vmax1) 
  -- ++(t4, vmax2) -- ++(t5, 0) -- ++(t6, -vmax2) 
  -- ++(t7, vmax3) -- ++(t8, 0) -- ++(t9, -vmax3);
\end{tikzpicture}
\end{document}

Answer 2

这是一种使用 pgfplots 的方法。

使用坐标只是提供数据的一种方式：

• 有时使用它们很简单
• 有时它们使用起来很乏味
• 您也可以提供 csv 文件，例如来自模拟或测量

\documentclass[10pt,border=3mm,tikz]{standalone}
\usepackage{pgfplots}

\begin{document}
 \begin{tikzpicture}
    \begin{axis}[
        title=Plotting data with pgfplots,
        ylabel=some unit,
        xlabel=some time,
    ]
    \addplot coordinates {  % 1st pulse; all points could be here
        (0,0) (.5,.25) (2.7,.25) (3.2,0)
    };
    \addlegendentry{1st pulse}
    
    \addplot coordinates {  % 2nd pulse; just for demonstartion purposes
        (3.2,0) (3.7,.125)(8.1,.125)(8.6,0)
        (9.1,-.25)(14.5,-.25)(15,0)
    };
    \addlegendentry{more pulses}
    
    \end{axis} 
 \end{tikzpicture}
\end{document}

Answer 3

这是手绘这种图画的方法。你应该阅读并多次尝试的教程是在 pgfmanual 中。

\documentclass[10pt,border=3mm,tikz]{standalone}

\begin{document}
 \begin{tikzpicture}
    % ~~~ pulses ~~~~~~~~~~~~~~~~~~~~~~~
    \draw (0,0) -- ++(0.1,2) -- ++(1,0) -- ++(0.1,-2)   % 1st pulse
        -- ++(0.1,1) -- ++(1.5,0) -- ++(0.1,-1)         % 2nd
        -- ++(0.1,-2) -- ++(2,0) -- ++(0.1,2)           % 3rd
        ;
        
    % ~~~ t-axis ~~~~~~~~~~~~~~~~~~~
    \draw[->,blue] (-1,0) -- (6,0) node[anchor=west]{$t$};
    
    % ~~~ ticks + labels ~~~~~~~~~~~~~~~~~~~~~~~
    \foreach \t in {0,1,2,...,5}
        \draw (\t,2pt) -- +(0,-4pt) node[anchor=north,teal]{$\t$};
        
 \end{tikzpicture}
\end{document}