在图形顶部的图表线条上添加图例

Question

我想将我的新结果显示在从旧论文中复制的图表上。我遇到了两个主要问题。

1.a/ 如果使用移位并第二次使用 \addlegendentry{My second}，则不会显示任何内容。1.b/ 如果我注释掉移位，则我有两个图例条目

2./ 图例中的标记与图线上的标记不一致

我是不是做错什么了？

顺便问一下：在这种情况下我可以使用样本图吗？

    \documentclass{standalone}
\usepackage{pgfplots}

\begin{document}
    \begin{tikzpicture}
        \begin{axis}[           
            hide axis,
            width=10cm,
%           scale only axis,
%           enlargelimits=false,
            xmin=0,xmax=15,ymin=0,ymax=13,
%           axis on top
            ]
    \addplot graphics[xmin=0,xmax=15,ymin=0,ymax=13] {figure2.png};
\addplot +[ %shift={(+33.2,+45.0)}, %only marks,
mark=*, very thick,
only marks,
color=orange, mark size=2] plot coordinates {
(1,4.94)
(1.2,5.44)
(1.4,5.85)
(1.6,6.17)
(1.8,6.44)
};
\addlegendentry{My first}

\addplot +[  shift={(+33.2,+45.0)}, %only marks,
mark=*, very thick,
only marks,
color=blue, mark size=2] plot coordinates {
    (0,0)
    (0.2,1.41)
    (0.4,2.55)
};
\addlegendentry{My second}
        \end{axis}
    \end{tikzpicture}
\end{document}

Answer 1

\documentclass[tikz, border=1cm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.18}
\begin{document}
\begin{tikzpicture}
\begin{axis}[           
hide axis,
width=10cm,
xmin=0, xmax=15,
ymin=0, ymax=13,
]
\addplot[forget plot] graphics[xmin=0, xmax=15, ymin=0, ymax=13] {example-image.png};
\addplot[
orange, very thick,
only marks, mark=*, mark size=2,
x filter/.expression={x+1}, %example number added
y filter/.expression={y+2}, %example number added
] plot coordinates {
(1,4.94)
(1.2,5.44)
(1.4,5.85)
(1.6,6.17)
(1.8,6.44)
};
\addlegendentry{My first}
\addplot[
blue, very thick,
only marks, mark=*, mark size=2,
x filter/.expression={x+3}, %example number added
y filter/.expression={y+4}, %example number added
] plot coordinates {
    (0,0)
    (0.2,1.41)
    (0.4,2.55)
};
\addlegendentry{My second}
\end{axis}
\end{tikzpicture}
\end{document}