def sv_diagram_data(chrom_string):
    if len(chrom_string.string) > 0:
        x, cn = sim.get_x_cn(sim.letters_to_positions(chrom_string.string))
        letters = set([l for l in chrom_string.string if l.isalnum()])
        return letters, cn, fusion_set(chrom_string)
    else:
        return None
def fusion_set(chrom_string):
    return set(sim.get_fusions(sim.letters_to_positions(chrom_string.string)))