def poi_vs_all(true_pep_iz, prep_result):
    """
    true_pep_iz refers to the full set of all peptides.

    This function returns remapped values of true_pep_iz such that
    each peptide that is from a POI keeps its true_pep_i
    whereas all other peptides are remapped to class 0, ie "OTHER"
    """

    df = prep_result.peps__pois()
    lut = df.pep_i.values
    other_mask = df.is_poi.values != 1
    lut[other_mask] = 0
    return lut[true_pep_iz]