The function is well defined in the whole region. But it just skips plotting the center region. I've tried PlotPoints, Mesh, Contours - it didn't help.
After making more contours. White hole is still there.
After zooming in the region suddenly reveals data.
How can I make it to plot central part in detail when zoomed out? Thank you in advance.
UPD: Yes, thanks, that's PlotRange :)