Figure 8

Approximation of the empirical score distribution of non-phosphorylated sites. The empirical score distribution was approximated using equations 16 and 17. With a correlation coefficient of 0.9988, the applied polynomial fit of 3^rd order provides a sufficiently accurate approximation of the expected false-positive rate. The parameters with respect to equation 17 are: u = -1.76847, λ₁ = -0.766775, λ₂ = 0.166677 and λ₃ = -0.0298602. The polynomial fit was calculated using the XMGRACE tool [81].