pgfplots 上的抛物线图

Question

我有一张抛物线图。为什么上面排版有“*10^{4}”？！如何将“20,000”打印为沿 x 轴的刻度标记？我试过了，xticklabels={$20,000$}但代码无法编译。

\documentclass{amsart}
\usepackage{amsmath}
\usepackage{amsfonts}

\usepackage{tikz}
\usetikzlibrary{calc,intersections}

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

\begin{document}

\begin{tikzpicture}
\begin{axis}[width=3in, height=3in, axis lines=middle, clip=false,
    axis lines=middle, clip=false,
    xmin=-1000,xmax=37320.5,
    ymin=-200000,ymax=725000,
    restrict y to domain=-200000:725000,
    xtick={20000},ytick={\empty},
    ticklabel style={font=\scriptsize},
    xticklabels={$20000$},
    axis line style={latex-latex},
    xlabel=$x$,ylabel=$y$,
    axis line style={shorten >=-12.5pt, shorten <=-12.5pt},
    xlabel style={at={(ticklabel* cs:1)}, xshift=12.5pt, anchor=north west},
    ylabel style={at={(ticklabel* cs:1)}, yshift=12.5pt, anchor=south west}
]


\addplot[samples=501, domain=-1000:37320.5] {-0.003*x^2 + 120*x - 500000};


%P = (25000, 625000) is a point on the parabola. The slope of the tangent line at P
%is -30. An equation for the tangent line at P is y = -30x + 1,375,000.
\coordinate (P) at (25000, 625000);
\coordinate (Q) at (137500/3, 0);

\end{axis}


%A "pin" is drawn to the parabola. 
\draw[draw=gray, shorten <=1mm, shorten >=1mm] (P) -- ($(P)!0.75cm!90:(Q)$);
\node[anchor=west, inner sep=0, font=\footnotesize] at ($(P)!0.75cm!90:(Q)$){\makebox[0pt][l]{$y=P(x)$}};

\end{tikzpicture}




\end{document}

Answer 1

正如符号 1 在问题下方的评论中所述，关键是设置scaled ticks=false，并且 PGFPlots 手册指出该关键：

允许从刻度标签中抽取常见指数线性轴。例如，如果您有刻度标签 20000；40000 和 60000，您可能希望节省一些空间并写入 2；4；6 以及单独的因子 '$\cdot 10^4$'。使用scaled ticks=true启用此功能。在 的情况下true，如果数据范围太大或太小，将触发刻度缩放。

而且由于数字已经按照您想要的方式显示出来，您无需再进行xticklabels任何说明。

（请注意，我对代码还做了一些其他的小改动，但我没有在这里评论。）

% used PGFPlots v1.14
\documentclass[border=15pt]{standalone}
\usepackage{pgfplots}
    \usetikzlibrary{calc}
    \pgfplotsset{compat=1.11}
\begin{document}
\begin{tikzpicture}
    \begin{axis}[
        width=3in,
        height=3in,
        axis lines=middle,
        xmin=-1000,
        xmax=37320.5,
        ymin=-200000,
        ymax=725000,
        xtick={20000},
        % ---------------------------------------------------------------------
        % you don't want the ticks/tick labels to be scaled
        scaled ticks=false,
%        % and the tick labels are shown by default the way you want them,
%        % so you don't need to specify them explicitely
%        xticklabels={$20000$},
        % ---------------------------------------------------------------------
        ytick={\empty},
        ticklabel style={font=\scriptsize},
        xlabel=$x$,
        ylabel=$y$,
        axis line style={
            latex-latex,
            shorten >=-12.5pt,
            shorten <=-12.5pt,
        },
        xlabel style={at={(ticklabel* cs:1)}, xshift=12.5pt, anchor=north west},
        ylabel style={at={(ticklabel* cs:1)}, yshift=12.5pt, anchor=south west},
    ]

        \addplot[samples=51,smooth,domain=-1000:37320.5] {-0.003*x^2 + 120*x - 500000};

        %P = (25000, 625000) is a point on the parabola. The slope of the tangent line at P
        %is -30. An equation for the tangent line at P is y = -30x + 1,375,000.
        \coordinate (P) at (25000, 625000);
        \coordinate (Q) at (137500/3, 0);

    \end{axis}

    %A "pin" is drawn to the parabola.
    \draw[draw=gray, shorten <=1mm, shorten >=1mm] (P) -- ($(P)!0.75cm!90:(Q)$);
    \node[anchor=west, inner sep=0, font=\footnotesize] at ($(P)!0.75cm!90:(Q)$){$y=P(x)$};

\end{tikzpicture}
\end{document}