calc_ranks_since_first_retained_disparity_with

calc_ranks_since_first_retained_disparity_with(focal: Union[HereditaryStratigraphicColumn, HereditaryStratigraphicSpecimen], other: Union[HereditaryStratigraphicColumn, HereditaryStratigraphicSpecimen], confidence_level: float = 0.95) → int | None

Determine generations since divergence with particular confidence.

How many depositions have elapsed along the focal column’s line of descent since the first mismatching strata at the same rank between focal and other?

Returns

int, optional

The number of depositions elapsed or None if no disparity (i.e., both columns have same number of strata deposited and the most recent stratum is common between focal and other).

Parameters

confidence_levelfloat, optional

With what probability should the true number of ranks since the first disparity be less than or equal to the returned estimate? Default 0.95.

Notes

Returns -1 if focal and other share no mismatching strata at common ranks but other has more strata deposited than focal.

The true number of ranks since the first disparity with other is guaranteed strictly less than or equal to the returned estimate when confidence_level < 0.5.