Mfcttrf

I wanted to draw an ellipse with top half dashed and bottom half solid but also filled. Is there a direct way to do this using the ellipse command from usetikzlibraryshapes?

What I do now, which feels like a trick, is to draw 2 arcs for the top and bottom half this way I can set one arc dashed and the other not. Then next draw an ellipse on top of them but without an edge, just filled. Like this

documentclass[tikz]standalone
usetikzlibraryshapes
begindocument
begintikzpicture

defxR1.25; %x radius of ellipse
defyR0.5; %y radius of ellipse

draw [dashed,domain=0:180] plot (xR*cos(x), yR*sin(x)); %top half
draw [domain=-180:0] plot (xR*cos(x), yR*sin(x)); %bottom half

fill[gray!20] (0,0) ellipse (xR and yR); %overlay with ellipse

endtikzpicture

enddocument

Is there a better way do this?

With arcs. I'd also fill the area first, this looks arguably better.

documentclass[tikz]standalone
begindocument
begintikzpicture

defxR1.25; %x radius of ellipse
defyR0.5; %y radius of ellipse

fill[gray!20] (0,0) ellipse (xR and yR); %overlay with ellipse
draw [dashed] (-xR,0) arc[start angle=180,end angle=0,x radius=1.25,y radius=0.5]; %top half
draw (-xR,0) arc[start angle=180,end angle=360,x radius=1.25,y radius=0.5]; %bottom half
endtikzpicture
enddocument

Or using two commands "only".

documentclass[tikz]standalone
begindocument
begintikzpicture
defxR1.25; %x radius of ellipse
defyR0.5; %y radius of ellipse
draw [dashed,fill=gray!20] (0,0) ellipse (xR and yR);
draw (-xR,0) arc[start angle=180,end angle=360,x radius=1.25,y radius=0.5]; %bottom half
endtikzpicture
enddocument

You could write styles that dash the first 50% (or whatever %) of the path:

documentclass[tikz]standalone
usetikzlibrarydecorations.markings
begindocument
begintikzpicture[draw only after/.style=preaction=decorate,decoration=markings,mark=at
position 0 with pgfmathsetmacromypoffpgfdecoratedpathlength*#1xdefmypoffmypoff
pgfmathsetmacromyplpgfdecoratedpathlengthxdefmyplmypl,
postaction=draw,dash pattern=on 0pt off mypoff on mypl]
draw [dashed,fill=gray!20,draw only after=1/2] (1.25,0)
arc[start angle=00,end angle=360,x radius=1.25,y radius=0.5]; 
endtikzpicture
enddocument