Parameter optimization for the gene expression networks. The standard deviation σ is given as a function of the total number of parameters p. The five curves correspond to the five model structures of eqs (5-9): dashed line: ; thick solid: ; dashed-dotted line: ; dotted line: ; thin solid line: m
. The number of parameters (p) depends on the connectivity per class (q) and the number of classes (C): p = (2q+4)C for , p = (2q+5)C for , p = (q+4)C for and , and p = (q+1)C for m
. The value of the minimum connectivity qm necessary to yield good data reproduction is indicated by a large circle. (a) Embryonic time series; the number of parameters p shown corresponds to connectivities q between 1 and 4; qm = 3; (b) full time series; the number of parameters p shown corresponds to connectivities q between 1 and 12; qm = 7.