OverlapPlus matching: after the overlap approach, the DNA copy number of unmatched genes is ‘estimated’ by interpolation of the gene dosage of the closest array CGH features. In both panels no feature overlaps with the gene. In the top panel the overlapPlus approach would interpolate the DNA copy number data between feature j-1 and j, as there is no breakpoint between them. In the bottom panel, however, the features j-1 and j are separated by a breakpoint, and the overlapPlus procedure will not interpolate.
van Wieringen et al. BMC Bioinformatics 2012 13:80 doi:10.1186/1471-2105-13-80