R2 = Manifold(2, 'R2', r'\mathbb{R}^2', start_index=1) Rect.<x,y> = R2.chart() U = R2.open_subset('U', coord_def={Rect : (y != 0, x > 0)}) RectU = Rect.restrict(U) Polar.<r,th> = U.chart(r'r:(0,+oo) th:(-pi,pi):\theta')
Polar
Polar.coord_range()