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pgf 奇怪的错误“缺失数字被视为零”

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pgf 奇怪的错误“缺失数字被视为零”

我正在准备一篇论文。我正在使用 Visual Studio Code 和 Miktex。在阅读了这里关于“缺失数字，视为零”的许多相关问题后，我仍然不明白为什么以下示例会导致这样的错误消息。我使用 Geobra Classic 生成此代码。

\documentclass[10pt]{article}
\usepackage{pgfplots}
\pgfplotsset{compat=1.15}
\usepackage{mathrsfs}
\usetikzlibrary{arrows}
\pagestyle{empty}
\begin{document}
\definecolor{ccqqqq}{rgb}{0.8,0,0}
\definecolor{qqwuqq}{rgb}{0,0.39215686274509803,0}
\begin{tikzpicture}[line cap=round,line join=round,>=triangle 45,x=1cm,y=1cm]
    \begin{axis}[
            x=1cm,y=1cm,
            axis lines=middle,
            xmin=-5.912600483813963,
            xmax=10.112505461619168,
            ymin=-5.0000004190058975,
            ymax=5.000000419005901,
            xtick={-5,-4,...,10},
            ytick={-5,-4,...,5},]
        \clip(-5.912600483813963,-5.0000004190058975) rectangle (10.112505461619168,5.000000419005901);
        \draw[line width=2pt,color=qqwuqq,smooth,samples=100,domain=-2.791287717641796:0.9999998864501113] plot(\x,{sqrt((\x)^(3)-6*(\x)+5)});
        \draw[line width=2pt,color=qqwuqq,smooth,samples=100,domain=1.791293439719924:10.112505461619168] plot(\x,{sqrt((\x)^(3)-6*(\x)+5)});
        \draw[line width=2pt,color=ccqqqq,smooth,samples=100,domain=-2.791287717641796:0.9999998864501113] plot(\x,{0-sqrt((\x)^(3)-6*(\x)+5)});
        \draw[line width=2pt,color=ccqqqq,smooth,samples=100,domain=1.791293439719924:10.112505461619168] plot(\x,{0-sqrt((\x)^(3)-6*(\x)+5)});
        \begin{scriptsize}
            \draw[color=qqwuqq] (-2.753604403186806,0.22489541633604176) node {$f$};
            \draw[color=ccqqqq] (-2.753604403186806,0.026150629806518583) node {$g$};
        \end{scriptsize}
    \end{axis}
\end{tikzpicture}
\end{document}

错误信息说：

<to be read again> 
                   n
l.26    \end{axis}
                
A number should have been here; I inserted `0'.
(If you can't figure out why I needed to see a number,
look up `weird error' in the index to The TeXbook.)

为什么我会得到缺失的数字，并将其视为零错误？

谢谢3000！

答案1

感谢大家，Ulrike Fischer 找到了我问题的答案。我只需要将我的函数更改为plot(\x,{sqrt(abs((\x)^(3)-6*(\x)+5))});

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