Cfrgtkky

I could not find information on this: How can I have the line shown above/in front of the marker? Right now it is plotted behind the diamond marker in the diagram as well as in the legend.

documentclass{standalone}

usepackage{xcolor, pgfplots}



begin{document}



begin{tikzpicture}

begin{axis}

addplot[mark=square*, mark options={fill=gray}] coordinates {(1,2)(2,1)};

legend{x};

end{axis}

end{tikzpicture}



end{document}

This would be the desired case:

There is a straightforward part: you can get the plot as desired by using mark layer. Just draw the marks on a layer that is behind the main plot. And then there is the part that requires tiny a bit more effort: make the legend comply. To this end, I slightly modified the legend image code. (I do not precisely know why one has to do this but given that the legend should usually be in front of the plots, it makes sense that the stuff in the legend goes on a different layer, and thus the layer of the mark gets readjusted.)

documentclass{standalone}

usepackage{xcolor, pgfplots}

pgfplotsset{compat=1.16}

begin{document}



begin{tikzpicture}

begin{axis}[set layers,mark layer=axis background,

legend image code/.code={

         draw [mark repeat=2,mark phase=2,#1] plot coordinates {

        (0cm,0cm) (0.3cm,0cm) (0.6cm,0cm)};

        draw [#1] (0cm,0cm) rectangle (0.5cm,0cm);

    }]

addplot[mark=square*, mark options={fill=gray}] coordinates {(1,2)(2,1)};

legend{x};

end{axis}

end{tikzpicture}

end{document}

Welcome to TeX.SE!

If you plot the points (but by tikz node and not pgfplot's mark) before adding the plot it is easy:

documentclass{standalone}

usepackage{xcolor, pgfplots}

usetikzlibrary{shapes}



begin{document}



begin{tikzpicture}

begin{axis}

node[diamond,fill,color=orange,inner sep=2pt] at (axis cs:1,2) {};

node[diamond,fill,color=red,inner sep=2pt] at (axis cs:2,1) {};

node[diamond,fill,color=green,inner sep=2pt] at (axis cs:1.8,1.2) {};

addplot[thick] coordinates {(1,2)(2,1)};

legend{x};

end{axis}

end{tikzpicture}



end{document}

PS: I am sure that pgfplots has a way too, but I don't really use it, so wait for another answer before accepting because I use mostly tikz and no pgfplots