def make_QC_header(coverage, identity, length):
    """ Create a header for the read QC file """

    cols = "\t".join(["dataset", "read_ID", "passed_QC", "primary_mapped",
                      "read_length", "fraction_aligned", "identity"])
    header = "\n".join(["# TALON run filtering settings:",
                        "# Min fraction read aligned: %f " % coverage,
                        "# Min read identity to reference: %f" % identity,
                        "# Min transcript length: %d" % length,
                        "# -------------------------------------------",
                        cols])

    return header