In this section we will introduce both models briefly. For the derivation of the formulas we refer to appendix A
The starting point of both methods is the notion that the experimental
output for some cell cycle trait ( 
) at time t is the average
output of all individuals (Creanor & Mitchison, 1982, 1994) distributed
over the cell cycle. Let 
be the distribution function describing
the collection of cells in state x at time t, and assume that 
is the unique value of the trait of an individual cell in state x, then
the average output can be written as
where 
is the set of attainable states. Our goal is to find from the experimental time series and experimental
information about the distribution . The methods differ in
assumptions about the distribution function in eq. (1).
