alifestd_is_ultrametric

alifestd_is_ultrametric(phylogeny_df: DataFrame, mutate: bool = False, *, atol: float = 0.0) → bool

Do all tips share the same origin_time (within atol)?

Tests the peak-to-peak (ptp) range of origin_time among tips against atol. Returns True for empty phylogenies. Raises ValueError if any tip’s origin_time is null/NaN.

Input dataframe is not mutated by this operation unless mutate set True.