readBed: Read a BED file and convert it to GRanges.
Description
The function reads a BED file that contains location and other information
on genomic features and returns a GRanges object.
The minimal information that the BED file has to have is chromosome,
start and end columns. it can handle all BED formats up to 12 columns.
location of the file, a character string such as: "/home/user/my.bed"
or the input itself as a string (containing at least one \n).
The file can end in .gz, .bz2, .xz, or .zip
and/or start with http:// or ftp://. If the file is not
compressed it can also start with https:// or ftps://.
track.line
the number of track lines to skip, "auto" to detect them
automatically or FALSE(default) if the bed file doesn't
have track lines
remove.unusual
if TRUE remove the chromosomes with unsual
names, such as chrX_random (Default:FALSE)
zero.based
a boolean which tells whether the ranges in
the bed file are 0 or 1 base encoded. (Default: TRUE)