VTT decision surface for an additional data partition. Decision boundary for VTT on the space of P(a)/N(a) and np(a) for one of the additional data partitions. Red and blue dots represent negative and positive abstracts. Dotted line represents surface that optimizes training data alone. VTT, variable trigonometric threshold.
Abi-Haidar et al. Genome Biology 2008 9(Suppl 2):S11 doi:10.1186/gb-2008-9-s2-s11