phred.py 文件源码

def proba_to_quality_solexa(pe):
    """prior v1.3 (ref: wikipedia
    https://en.wikipedia.org/wiki/FASTQ_format
    """
    if pe > 1:
        pe = 1
        return -5

    if pe <1e-90:
        pe = 1e-90
    Qs = -10 * log10(pe/(1-pe))
    if Qs > 62:
        Qs = 62
    if Qs < -5:
        Qs = -5
    return Qs