2019独角兽企业重金招聘Python工程师标准>>> 
\documentclass[border=0,tikz]{standalone}
\usetikzlibrary{arrows.meta}
\usepackage{scalerel} %\scaleobj{1.5}{} 缩放公式大小
\begin{document}
\begin{tikzpicture}
\draw[arrows={-Stealth[length=5pt, inset=4.5pt]}] (-0.55,0) -- (3.75,0)node (xaxis) [below=-0.5mm] {$\scaleobj{0.5}{x}$};
\draw[arrows={-Stealth[length=5pt, inset=4.5pt]}] (0,-0.55) -- (0,1.35)node (yaxis) [left=-0.75mm] {$\scaleobj{0.5}{y}$};
\draw (-0.12,-0.12) node {$\scaleobj{0.5}{o}$};
\draw[color=red,scale=0.25, domain=-1.7:2*4.0, smooth, variable=\t ]
plot ( {2*(\t-sin(\t r))}, {2*(1-cos(\t r))} );
\draw (1.5,0)--(1.5,1) coordinate[pos=0.5] (a_c);
\draw[line width=0.3pt] (1.48,0.5)--(1.52,0.5);
\draw(1.5,0) -- (a_c) node[midway,right=-1mm] {$\scaleobj{0.45}{a}$};
\draw(a_c) -- (1.5,1) node[midway,right=-1mm] {$\scaleobj{0.45}{a}$};
\draw (0.5,0.5) circle [radius=0.5];
\draw (0.5,0)--(0.5,1) coordinate[pos=0.5] (a_z);
\draw[line width=0.3pt] (0.48,0.5)--(0.52,0.5);
\draw (0.5,0) -- (a_z) node[midway,right=-1mm] {$\scaleobj{0.45}{a}$};
\draw (a_z) -- (0.5,1) node[midway,left=-1mm] {$\scaleobj{0.45}{a}$};
\end{tikzpicture}
\end{document}
选自 How can I draw this cycloid diagram with TikZ?
\documentclass[pstricks,border=15pt,12pt]{standalone}
\usepackage{fp}
\FPeval\XMin{0-1}
\FPeval\XMax{2*pi+1}
\usepackage{pst-plot,pst-node}
\psset
{
algebraic,
linejoin=1,
labels=none,
ticks=none,
dimen=m,
linecolor=lightgray,
linewidth=2\pslinewidth,
}
\def\x{(t-sin(t))}
\def\y{(1-cos(t))}
\pstVerb{/I2P {AlgParser cvx exec} bind def}
\def\Atom#1{%
\begin{pspicture}(\XMin,-1)(\XMax,3)
\psaxes(0,0)(\XMin,-1)(\XMax,3)[$x$,0][$y$,90]
\pnode(!#1 1){C}
\pnode(!#1 /t ED \x I2P \y I2P){P}
\psparametricplot[linecolor=red]{\XMin}{\XMax}{\x|\y}
\pscircle[linecolor=blue](C){1}
% additional accessories
\psline(C|0,0)(C)(P)
\psline[linecolor=green](!#1 0)
\psarcn[linecolor=green,origin={C}](C){1}{-90}{(P)}
\pscircle*[linecolor=red](P){2pt}
\pscircle*[linecolor=blue](C){2pt}
\end{pspicture}}
\begin{document}
\multido{\n=0.0+0.1}{21}{\Atom{\n\space Pi mul}}
\end{document}