def idfp(df, id_global_assignment):
    """ID measures: Number of false positive matches after global min-cost matching."""
    del df  # unused
    rids, cids = id_global_assignment['rids'], id_global_assignment['cids']
    return id_global_assignment['fpmatrix'][rids, cids].sum()
ID measures: Number of false positive matches after global min-cost matching.
motmetrics/metrics.py