where 𝐵(𝑎, 𝑏) is the Beta function, and where 𝐼x(𝑎, 𝑏) is the regularized incomplete Beta function.
Range 0 ≤ 𝑥 - 𝜃 < ∞
Shape1 parameter 𝜈 > 0, integer, first degrees of freedom
Shape2 parameter 𝑤 > 0, integer, second degrees of freedom
Threshold parameter 𝜃 < 𝑚𝑖𝑛(𝑥)