<div dir="ltr"><span style="font-size:12.8000001907349px">Hi all, </span><div style="font-size:12.8000001907349px"><br></div><div style="font-size:12.8000001907349px">I have been trying to plot a circle of a given radius around the boundary of a collapsing cloud to track its evolution. </div><div style="font-size:12.8000001907349px">Usually in matplotlib, I would just draw a circle using a xy meshgrid, but if I do this using matplotlib the circle would be on a separate figure and not overlaid on the yt plot. So I tried using a PlotWindow to separate the data and the yt plot  but I get this error:</div><div style="font-size:12.8000001907349px"><br></div><div style="font-size:12.8000001907349px"><div style="display:flex;color:rgb(0,0,0);font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:14px;line-height:20px"><div style="min-width:11ex;padding:0.4em;margin:0px;font-family:monospace;text-align:right;line-height:1.21429em;color:rgb(0,0,128);border-top-width:1px;border-top-style:solid;border-top-color:transparent">In [92]:<span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">yt</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">.</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">visualization</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">.</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">plot_window</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">.</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">PlotWindow</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">(</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">proj</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">,(</span><span style="font-family:inherit;line-height:inherit;font-size:inherit;color:rgb(170,34,255);font-weight:bold;background-color:transparent">-</span><span style="font-family:inherit;line-height:inherit;font-size:inherit;color:rgb(0,136,0);background-color:transparent">1e5</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">,</span><span style="font-family:inherit;line-height:inherit;font-size:inherit;color:rgb(0,136,0);background-color:transparent">1e5</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">,</span><span style="font-family:inherit;line-height:inherit;font-size:inherit;color:rgb(170,34,255);font-weight:bold;background-color:transparent">-</span><span style="font-family:inherit;line-height:inherit;font-size:inherit;color:rgb(0,136,0);background-color:transparent">1e5</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">,</span><span style="font-family:inherit;line-height:inherit;font-size:inherit;color:rgb(0,136,0);background-color:transparent">1e5</span><span style="font-family:inherit;line-height:inherit;color:inherit;font-size:inherit;background-color:transparent">))</span></div></div><div style="display:flex;font-family:'Helvetica Neue',Helvetica,Arial,sans-serif;font-size:14px;line-height:20px"><div style="display:flex"><div style="padding:0px;display:flex"><div style="padding:0.4em 0.4em 0px;line-height:1.21429em"><pre style="white-space:pre-wrap;padding:0px;font-size:inherit;border-radius:0px;margin-top:0px;margin-bottom:0px;line-height:inherit;word-break:break-all;word-wrap:break-word;border:0px;vertical-align:baseline;background-color:transparent"><span style="color:rgb(139,0,0)">AttributeError</span><font color="#000000">: 'ProjectionPlot' object has no attribute '_key_fields'
</font></pre><div style="color:rgb(0,0,0)"><br></div></div></div></div></div></div><div style="font-size:12.8000001907349px">In general, is there to get my RAMSES data loaded into yt as a numpy array with actual numbers in them then feed it into matplotlib to do this task? or alternatively, is there a simpler way to do this directly on yt using annotate_contour or some other yt function?</div><div style="font-size:12.8000001907349px"><br></div><div style="font-size:12.8000001907349px">Thank you.</div><div style="font-size:12.8000001907349px"><br></div><div style="font-size:12.8000001907349px">Regards,</div><div style="font-size:12.8000001907349px">Doris</div><div style="font-size:12.8000001907349px">----</div><div style="font-size:12.8000001907349px">Code for generating the attached plot, the green boundary line is in theory what I am trying to draw.</div><div style="font-size:12.8000001907349px"><br></div><div style="font-size:12.8000001907349px"><div>ds= yt.load("../../bin/output_00002/info_00002.txt")</div><div>proj = yt.ProjectionPlot(ds, "y", "density",window_size=10)</div><div>proj.set_cmap("density","rainbow")</div><div>proj.annotate_velocity()</div><div>proj.show()</div></div></div>