The number fp is added to the total frequency,
𝛿f,g, only when p and g interact (when
𝕀interact(p,g) = 1). This effective interaction
frequency, 𝛿f,g, takes us closer to estimating
interaction affinity between a feature and an interactor. To further
account for SecP and feature promiscuity, we implement an estimate of
the tendency for f and g to interact. We modeled the interaction
frequency 𝛿f,g with a Poisson distribution.