GenoSet contains a number of functions that work on segments. Many work on a data.frame of segments, like segTable and runCBS. This function converts one of these tables in a GRanges. The three columns specifying the ranges become the GRanges and all other columns go into the 'mcols' portion of the GRanges object.
data.frame with loc.start, loc.end, and chrom columns, like from segTable or runCBS