mjhjmtu

I have following code:

begintikzpicture
beginpolaraxis[xtick=0,90,180,270, ytick=0,1, ymax=1.5, xticklabel=pgfmathprintnumberticksidegree, set layers=default]
addplot[thick,fill=gray,draw=none,opacity=0.5, domain=0:360,
samples=360,]1;
addplot+[thick, mark=none, >->] table[col sep=comma,x=ang,y=abs] images/tikz/stability/stable.csv;
addplot+[thick, mark=none, >->, orange] table[col sep=comma,x=ang,y=abs] images/tikz/stability/instable.csv;
endpolaraxis
endtikzpicture

It draws some plots to a polar plot. With the first plot I try to fill the inner of the unit circle. However, I have not succeeded in doing so. I want the circle to be behind the axis. For this, I tried set layers in the options of the axis environment.

The first problem I experience is that: set layers=defautl and set layers should have the same effect, according to the documentation, but they don't. With set layers (without default), the axes vanish. with default the axes stay.

With the key on layer=axis background I tried to move the first plot behind the axes, as described here.

This does not work because the layer is unknown. I then tried set layers=standard. With this setting, the layer name is known, but the axes disappear again.

Can someone tell me, how to draw a plot behind polar axes?

Thank you

EDIT:

I've created a mimimal (not) working example with three varieties of code. The first two images should create the same output but they don't. The last one doen't do anything.

documentclass[tikz]standalone
usepackagepgfplots
pgfplotssetcompat=1.16
usepackagepgfplotstable
usepgfplotslibrarypolar
usepackagetikz

begindocument
begintikzpicture
beginpolaraxis[xtick=0,90,180,270, ytick=0,1, ymax=1.5, set 
layers=default]
addplot[thick,fill=gray,draw=none,opacity=0.5, domain=0:360,
samples=360,]1;
endpolaraxis
endtikzpicture

begintikzpicture
beginpolaraxis[xtick=0,90,180,270, ytick=0,1, ymax=1.5, set 
layers]
addplot[thick,fill=gray,draw=none,opacity=0.5, domain=0:360,
samples=360,]1;
endpolaraxis
endtikzpicture

begintikzpicture
beginpolaraxis[xtick=0,90,180,270, ytick=0,1, ymax=1.5, set 
layers=standard]
addplot[thick,fill=gray,draw=none,opacity=0.5, domain=0:360,
samples=360, on layer=axis background]1;
endpolaraxis
endtikzpicture
enddocument

Now I can confirm your observation: the layers on polar plots do not work as expected. As a workaround, one can draw the grid by hand on the axis layer.

documentclass[tikz,3.14mm]standalone
usepackagesiunitx
usepackagepgfplots
pgfplotssetwidth=7cm,compat=1.16
usepgfplotslibrarypolar 
begindocument
begintikzpicture
beginpolaraxis[xtick=0,90,180,270, ytick=0,1, ymax=1.5,
xticklabel=pgfmathprintnumberticksidegree,
 axis on top,grid style=draw=none]
addplot[thick,fill=red,draw=none,opacity=0.5, domain=0:360,
samples=360,]1;
% draw grid by hand
beginscope[on layer=axis lines,thin,gray]
draw(180,2) -- (0,2) (90,2) -- (270,2) (0,0);
addplot[domain=0:360,samples=60,smooth]1;
endscope

beginscope[on layer=axis foreground]
addplot[thick,domain=0:360] sin(x);
endscope
% addplot+[thick, mark=none, >->] table[col sep=comma,x=ang,y=abs] images/tikz/stability/stable.csv;
% addplot+[thick, mark=none, >->, orange] table[col sep=comma,x=ang,y=abs] images/tikz/stability/instable.csv;
endpolaraxis
endtikzpicture
enddocument

As you see, the filled circle is on the background, i.e. behind the grid, but the plot is on the foreground.