Fig. 4: Dimensionless Amirian model (Eq. 3, Pmax = 1, α = 1, Iα = 1) representing the range of observed PI curves with photoinhibition, illustrated using 5 quantiles (5%, 25%, 50%, 75%, 95%) of non-dimensionalized Iβ and β = 1/Iβ values.

The dimensionless value of P(I = Iβ) is tanh(1) ≈ 0.76.