CalcNumStrataRetainedExact

class CalcNumStrataRetainedExact

Functor to provide member function implementation in Policy class.

__init__(policy_spec: PolicySpec | None) → None[source]

Methods

__call__(policy: PolicyCouplerBase, num_strata_deposited: int) → int[source]

Exactly how many strata are retained after n deposited?

The calculation can be written mathematically as,

weight of binary expansion of n (i.e., #1’s set in binary repr) + sum(

floor( log2(n//r) ) for r from 1 to r inclusive

) + 1

where

n = num_strata_deposited - 1 r = resolution

This expression for exact number deposited was extrapolated from

and is unit tested extensively.

Note that the implementation must include a special case to account for n < r causing log2(0). In this case, the number of strata retained is equal to the number deposited (i.e., none have been discarded yet).

__init__(policy_spec: PolicySpec | None) → None[source]