Figure 1
From: Beyond microarrays: Finding key transcription factors controlling signal transduction pathways
Cost transformation function. Different variants of the cost transformation function f(C Pij ) for different values of h – "pathway persistence" (marked by different functions x1-h, h = 0.0, 0.2,...1.0). Under h = 1 the effect is maximal, since the cost of adding a new path that belongs to a known pathway does not depend on the length of the path and is always equal to 1.0. Under these conditions the search will stay within known pathways only.