Effects of the spatial distribution of X-ray emitting gas on the behavior of R for six helium-like ions: C v (top left), N vi (middle left), O vii (bottom left), Ne ix (top right), Mg xi (middle right) and Si xiii (bottom right) for each of our hypothetical stars with average effective temperature of 10 000, 20 000, 30 000 and 40 000 K (red, green, blue, and purple respectively). R / R₀ is plotted versus inner radius of gas in inverse radius u₀. The substitution of variables, u = r_⋆ / r, simplifies the calculation. The solid line indicates how much R is depressed from its nominal value if the gas is distributed from r = ∞ (u = 0) to r = r₀ (u = u₀). The dotted line shows the results if hot gas exists only at u₀. The value or the dotted line at u₀ = 1 / 2 is equivalent to our fiducial value elsewhere of r_gas = 2r_⋆ at zero displacement phase.