Expand description
Repeat statistics, case-clustered bootstrap intervals and noise bands (spec 029, 3.3.2 to 3.5).
Pure functions over per-case measures: a metric’s contribution from each case in each run, in manifest order and run order. Every value is determined by the measures, the configuration and the seed, through the in-crate generator, exact integer ranks and binary64 addition, subtraction, multiplication, division and square root in the fixed orders stated here: no fused multiply-add and no transcendental function, so the figures are bit-identical on every target.
Nothing is dropped or defaulted: an unknown run value makes the across-run statistics unknown, an undefined resample makes the interval unknown with its count, and an unknown input makes a band unknown, never the floor or zero.
Structs§
- Bootstrap
- The bootstrap’s declared inputs (3.3.1).
- Metric
Cases - A metric’s contributions:
cases[case][run],Nonewhere the case did not enter the metric’s denominator in that run. - RunStats
- Per-run values and the across-run statistics of one metric (3.3.2, 3.3.3).
Enums§
- Band
- A noise band, or why there is none.
- Basis
- Where a band came from (3.5.4).
- Contribution
- One case’s contribution to one metric in one run.
- Figure
- A figure, or why there is none.
- Form
- How a metric decomposes into per-case contributions (3.2.2).
- Interval
- A percentile interval, or why there is none.
- Stats
Error - Why statistics were refused.
Constants§
- MAX_
BOOTSTRAP_ WORK - The most work one cohort’s bootstrap may take:
B * C * N(3.4.8). - MAX_
DENOMINATOR - The largest denominator one case contributes in one run. Integer sums
are kept in
u128: at mostu32::MAXper contribution, 64 runs and fewer than 2^64 drawn cases stay below 2^102, so no sum can overflow, whatever the number of cases. - MAX_
LEVEL_ UNITS - MAX_
RUNS - The most runs in a repeat set (3.1.1).
- MIN_
LEVEL_ UNITS - The level’s bounds in Decimal units, [0.5, 0.999] (3.3.1).
Functions§
- across_
runs mean,sd,minandmaxof per-run values (3.3.2), in run order. Any unknown value makes all four unknown, naming the runs;sdof a single run is unknown except for deterministic replay (3.5.3).- band
max(derived, floor)(3.5.1 to 3.5.3). An unknown input is an unknown band, never the floor or zero. For areplayset ak_sdband is the floor with basisdeterministic_replay: replaying the same retained outputs varies by nothing.- check_
shape - Every case has exactly
runsentries and every contribution has the metric’s form. - intervals
- Case-clustered percentile bootstrap intervals for every metric of one
cohort (3.4.1, 3.4.5, 3.4.7). All metrics share the cohort’s cases and
its stream
cohort/<name>, so they use the sameBresamples. - percentile_
ranks - One-based ranks of the lower and upper percentile bounds among
Bsorted values, in exact integer arithmetic (3.4.7). - run_
stats - Per-run values,
mean,sd,min,maxandpooledof one metric over its cohort (3.3.2, 3.3.3).deterministicis thereplaysource, whosesdis exactly 0 for a single run (3.5.3).