Functions with the chunkSize parameter work best with file-backed
matrices such as BEDMatrix objects. To avoid loading the whole,
potentially very large matrix into memory, these functions will load chunks
of the file-backed matrix into memory and perform the operations on one
chunk at a time. The size of the chunks is determined by the
chunkSize parameter. Care must be taken to not set chunkSize
too high to avoid memory shortage, particularly when combined with parallel
computing.
BEDMatrix-class as an example of a file-backed
matrix.