使用一个 \addplot 图形在 pgfplot 中插入多个图例

Question

我希望图例与图表中的线图相匹配。我参考了很多图例问题，但我找不到一个试图为单个外部图形文件制作多个图例的问题。如果能得到一些帮助，我将不胜感激。这是带有附加图像文件的 MWE。

            \documentclass{article}

            \usepackage{graphicx}
            \usepackage{epstopdf}
            \usepackage{pgfplots}

            \begin{document}

            \begin{tikzpicture}
            \begin{loglogaxis} [
            width=\textwidth,
            enlargelimits = false,
            xmin = 0.0078,
            xmax = 32,
            ymin = 0.78e-8,
            ymax=109008.9,
            max space between ticks = 60,
            axis on top,
            xlabel = Frequency (Hz),
            ylabel = Power spectral density (dB),
            ]
            \addplot graphics [ 
                        xmin = 0.0078,
                        xmax = 32,
                        ymin = 0.78e-8,
                        ymax=109008.9,
                        ]
                        {psd_WsBlroot1.png};
                        \addlegendimage{draw=black,mark=none, line width=3pt, color=black},
                        \addlegendentry{Lidar wind speed 50m},
                        \addlegendimage{line width=3pt, color=gray},
                        \addlegendentry{Blade1 root bending moment},
            \end{loglogaxis}
            \end{tikzpicture}

            \end{document}

1

Answer 1

您只需要在添加默认线条定义之前创建图例即可\addplot。（我在复制图形文件时重命名了它。对此我很抱歉。）

\documentclass{article}

        \usepackage{graphicx}
        \usepackage{epstopdf}
        \usepackage{pgfplots}

        \begin{document}

        \begin{tikzpicture}
        \begin{loglogaxis} [
        width=\textwidth,
        enlargelimits = false,
        xmin = 0.0078,
        xmax = 32,
        ymin = 0.78e-8,
        ymax=109008.9,
        max space between ticks = 60,
        axis on top,
        xlabel = Frequency (Hz),
        ylabel = Power spectral density (dB),
        ]
        \addlegendimage{draw=black,mark=none, line width=3pt, color=black},
        \addlegendentry{Lidar wind speed 50m},
        \addlegendimage{line width=3pt, color=gray},
        \addlegendentry{Blade1 root bending moment},
        \addplot graphics [
                    xmin = 0.0078,
                    xmax = 32,
                    ymin = 0.78e-8,
                    ymax=109008.9,
                    ]
                    {images/graph.png};

        \end{loglogaxis}
        \end{tikzpicture}

        \end{document}