writeBigwig: Write BigWig files of Repli-seq assays
In CL-CHEN-Lab/RepliSeq: Repliseq

writes one BigWig file per fraction in the provided Repli-seq assay

writeBigwig(
  rs_assay,
  path_file,
  sample_name,
  chromsizes,
  wiggle_start,
  wiggle_step,
  wiggle_span,
  system_separator = "/"
)

`rs_assay`	a Repli-seq assay (data.frame) loaded with readRS() and formatted as chr,start,stop,S1,...,Sx (or S0)
`path_file`	a path to the files to write
`sample_name`	a string for the file names
`chromsizes`	path to the chromsizes file to pass to WigToBigWig as argument
`wiggle_start`	a numeric value for wiggle header
`wiggle_step`	a numeric value for wiggle header
`wiggle_span`	a numeric value for wiggle header
`system_separator`	default is "/" as dedicated for linux file system