def SegmentMin ( a , ids ) : func = lambda idxs : np . amin ( a [ idxs ] , axis = 0 ) return seg_map ( func , a , ids ) ,
python argmin of all min elements
Segmented min op .
def SegmentMin(a, ids):
    """
    Segmented min op.
    """
    func = lambda idxs: np.amin(a[idxs], axis=0)
    return seg_map(func, a, ids),