Figure 3.

A distribution of residuals obtained from the conventional population PK analysis with the normal proportional residual error model is overlaid by a normal density curve (blue dashed line). A three-component mixture density curve is represented by black solid line on the right panel, which is defined by ${\sum }_{q=1}^Q{w}_q{d}_q({\mathit{\psi }}_{\mathit{q}})$, where Q = 3, d₁ = N(0, τ₁), d₂ = N(0, τ₂) * Ga(a, b), d₃ = N(0, τ₃) * NGa(c, d), w₁ = 0.66, w₂ = 0.24, w₃ = 0.10, τ₁ = τ₂ = 0.09, τ₃ = 9, a = c = 1, and b = d = 0.2. These three components are separately presented by blue (d₁), red (d₂) and green (d₃) dashed lines, respectively, on the left panel.