foreach 中的 PGFplots 生成多个图形

Question

我使用 foreach 命令来生成多个图形。我的代码如下：

\documentclass[border=5mm,tikz]{standalone}
\usepackage[portuguese]{babel}
\usepackage[utf8]{inputenc}
\usepackage{tikz,pgfplots}
\usepackage{amsmath}


\begin{document}

\def\r{1}
\foreach \b in {0,0.5,...,6.5}{ 
\begin{tikzpicture}[xscale=1.4,yscale=1.4]
\begin{axis}[xmin = -1, xmax = 14,
    ymin = -0.5, ymax = 3,
    axis lines=middle,
    axis equal image,
    grid,
    xtick distance = 2,
    ytick distance = 1,
    xlabel=$x$,
    ylabel=$y$,
    samples=201,
    every axis x label/.style={
    at={(ticklabel* cs:1.03)}},
    every axis y label/.style={
    at={(ticklabel* cs:1.1)}},
    ]
    \addplot[thick,domain=0:2*pi] ({\b+\r*cos(deg(x))},{\r+\r*sin(deg(x))});
    \addplot[blue,domain=0:\b,thick,densely dotted] ({\r*x - \r*sin(deg(x))},{\r*1-\r*cos(deg(x))});
     \addplot[mark=*,mark size=1.5pt,blue] coordinates  { ( {\r*(\b-sin(deg(\b)))} , {\r*(1-cos(deg(\b)))} ) };
     \addplot[mark=*,mark size=1.5pt,red] coordinates {(\b,\r)};
\end{axis}
\end{tikzpicture}
}

\end{document}

我的目的是为每个 \b 值生成一个新的不同图形（独立）。

但是，我注意到 PGFplots 和 \foreach 不起作用。有人能帮帮我吗？

Answer 1

使用 没有问题foreach。问题是 对于\b=0第二个域来说\addplot没有意义。

\documentclass[border=5mm,tikz]{standalone}
%\usepackage[portuguese]{babel}
\usepackage[utf8]{inputenc}
\usepackage{pgfplots}
\pgfplotsset{compat=1.17} 
\usepackage{amsmath}


\begin{document}

\def\r{1}
\foreach \b in {0,0.5,...,6.5}
{\begin{tikzpicture}%[xscale=1.4,yscale=1.4]
\begin{axis}[xscale=1.4,yscale=1.4,
    xmin = -1, xmax = 14,
    ymin = -0.5, ymax = 3,
    axis lines=middle,
    axis equal image,
    grid,
    xtick distance = 2,
    ytick distance = 1,
    xlabel=$x$,
    ylabel=$y$,
    samples=201,
    every axis x label/.style={
    at={(ticklabel* cs:1.03)}},
    every axis y label/.style={
    at={(ticklabel* cs:1.1)}},
    ]
    \addplot[thick,domain=0:2*pi] ({\b+\r*cos(deg(x))},{\r+\r*sin(deg(x))});
    \ifdim\b pt>0pt
     \addplot[blue,domain=0:\b,thick,densely dotted] ({\r*x - \r*sin(deg(x))},
        {\r*1-\r*cos(deg(x))});
    \fi     
    \addplot[mark=*,mark size=1.5pt,blue] coordinates  { ( {\r*(\b-sin(deg(\b)))} , {\r*(1-cos(deg(\b)))} ) };
    \addplot[mark=*,mark size=1.5pt,red] coordinates {(\b,\r)};
\end{axis}
\end{tikzpicture}
}

\end{document}