FA-69074 / Tide and marine navigation tables / Member archive

Tidal height window: Window opens at the next sample instead of the crossing · case 04

Windows open late by up to one sample interval.

Member previewVariant 4 · 3 implementations · 7 checks per implementation

Case contract

Input [ts, hs, req]: sample times (minutes) and heights. Return the list of [start, end] intervals where height>=req, with crossing times linearly interpolated and rounded conservatively inward (start up, end down, 1e-9 tolerance); windows that vanish after rounding are dropped. A window open at the first sample starts at ts[0]; one still open at the end closes at ts[-1].

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
tidal height window [[0, 60, 120, 180, 240], [2.5, 2.6, 2.0, 2.4, 2.8], 2.5]	`[[0, 70], [240, 240]]`	`[[0, 70], [195, 240]]`	Failed

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