FA-68939 / Tide and marine navigation tables / Member archive

Secondary port differences: Height difference interpolates from the spring value · case 04

Heights are corrected with the neap difference on spring days.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Input dict: standard port HW time hw (minutes of day), height hh, today range rng, mean spring/neap ranges sr/nr, time differences ts/tn (spring/neap, minutes) and height differences hs/hn. Interpolation factor k=(rng-nr)/(sr-nr) clamped to [0,1]; difference = neap+(spring-neap)*k. Time is wrapped to [0,1440) and rounded to whole minutes half up; height rounded to 2 decimals. Return [minutes, height].

Why this case matters

Tide tables and passage plans turn published predictions into go/no-go decisions about depth, clearance and timing.

One recorded failure

Sample boundary fixture

This sample comes from the broken implementation of a controlled reproducer.

Boundary fixture	Actual	Expected	Outcome
secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.1, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}	`[590, 3.72]`	`[590, 3.68]`	Failed

MEMBER ARCHIVE

The complete case is available to members.

This record includes three runnable implementations, regression fixtures, execution results, and source hashes.

Member access is invitation-based. Sign in with your invited account to inspect the sources.