Helper for merging segments in the second case of FinalizeSmallSegments. Returns the updated large_segments data frame with segments appropriately merged (or not... depending on parameters).

Given the large_segments data, a large_segment j, and a small_segment small_segment, we merge the large segment with the small_segment according to various criteria. First, if their ratio_median difference is below the threshold, then we typically merge large and small. If not, then small segment is separately added into the large_segments frame. Also, where exactly in the large_segments frame we add this new data depends on end_of_file. For example, if it is TRUE, then there are no other large segments after j, so we row-bind all of large_segments to the new data. If FALSE, then we 'squeeze' the new data between j-1 and j+1.

Usage

MergeSegmentsTwo(
  granges_obj,
  small_segment,
  large_segments,
  j,
  below_thr,
  end_of_file
)

Arguments

granges_obj: A GRanges object: is used as reference to obtain true genomic data from specified regions.
small_segment: An array: the given small segment that might be merged into the large_segments frame.
large_segments: A data frame: segment data. Initially contains only segments with size >= 3Mb, but as we merge small segments into it, smaller segments are progressively added.
j: An integer/index: the position of the large segment we're comparing with small_segment, within large_segments.
below_thr: A boolean: whether large_segment and small_segment ratio_median difference is below the threhsold.
end_of_file: A boolean: whether there's any large segments after j.