FAILURE MAP
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FA-68921 / Tide and marine navigation tables / Open access

Secondary port differences: Differences are extrapolated beyond spring and neap · case 01

Exceptional ranges produce time differences outside the published pair.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The interpolation factor is not clamped to [0,1].

THE FAILURE

The interpolation factor is not clamped to [0,1].

Unsuccessful approach: Clamping only the upper end still extrapolates below neaps.

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.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    k=(x['rng']-x['nr'])/(x['sr']-x['nr'])
    k=k
    dt=x['tn']+(x['ts']-x['tn'])*k
    dh=x['hn']+(x['hs']-x['hn'])*k
    t=math.floor(x['hw']+dt+0.5)
    t=t%1440
    return [t,round(x['hh']+dh,2)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('secondary port differences {"hw": 20, "hh": 3.0, "rng": 1.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 20, 'hh': 3.0, 'rng': 1.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [40, 2.8]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 1.8, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 1.8, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [620, 3.9]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 2.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [611, 3.83]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.4, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 2.4, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [606, 3.8]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 3.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [593, 3.7]), ('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}', {'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, 3.68]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.6, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 3.6, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [579, 3.6])], [('secondary port differences {"hw": 700, "hh": 5.0, "rng": 5.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 700, 'hh': 5.0, 'rng': 5.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [665, 4.4]), ('secondary port differences {"hw": 1425, "hh": 4.0, "rng": 1.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1425, 'hh': 4.0, 'rng': 1.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 3.8]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 3.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [593, 3.7]), ('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}', {'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, 3.68]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.6, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 3.6, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [579, 3.6]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 4.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 4.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [565, 3.5]), ('secondary port differences {"hw": 10, "hh": 3.8, "rng": 3.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 10, 'hh': 3.8, 'rng': 3.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [1422, 3.25])], [('secondary port differences {"hw": 1425, "hh": 4.0, "rng": 1.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1425, 'hh': 4.0, 'rng': 1.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 3.8]), ('secondary port differences {"hw": 300, "hh": 2.2, "rng": 0.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 300, 'hh': 2.2, 'rng': 0.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [320, 2.0]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 4.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 4.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [565, 3.5]), ('secondary port differences {"hw": 10, "hh": 3.8, "rng": 3.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 10, 'hh': 3.8, 'rng': 3.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [1422, 3.25]), ('secondary port differences {"hw": 1430, "hh": 4.4, "rng": 2.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1430, 'hh': 4.4, 'rng': 2.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 4.17]), ('secondary port differences {"hw": 20, "hh": 3.0, "rng": 1.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 20, 'hh': 3.0, 'rng': 1.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [40, 2.8]), ('secondary port differences {"hw": 700, "hh": 5.0, "rng": 5.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 700, 'hh': 5.0, 'rng': 5.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [665, 4.4])], [('secondary port differences {"hw": 30, "hh": 4.9, "rng": 4.7, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 30, 'hh': 4.9, 'rng': 4.7, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [1435, 4.3]), ('secondary port differences {"hw": 20, "hh": 3.0, "rng": 1.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 20, 'hh': 3.0, 'rng': 1.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [40, 2.8]), ('secondary port differences {"hw": 700, "hh": 5.0, "rng": 5.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 700, 'hh': 5.0, 'rng': 5.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [665, 4.4]), ('secondary port differences {"hw": 1425, "hh": 4.0, "rng": 1.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1425, 'hh': 4.0, 'rng': 1.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 3.8]), ('secondary port differences {"hw": 300, "hh": 2.2, "rng": 0.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 300, 'hh': 2.2, 'rng': 0.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [320, 2.0]), ('secondary port differences {"hw": 600, "hh": 4.0, "rng": 3.0, "sr": 4.0, "nr": 2.0, "ts": -35, "tn": 20, "hs": -0.5, "hn": -0.1}', {'hw': 600, 'hh': 4.0, 'rng': 3.0, 'sr': 4.0, 'nr': 2.0, 'ts': -35, 'tn': 20, 'hs': -0.5, 'hn': -0.1}, [593, 3.7]), ('secondary port differences {"hw": 610, "hh": 3.5, "rng": 3.0, "sr": 4.0, "nr": 2.0, "ts": -12, "tn": 25, "hs": -0.4, "hn": 0.1}', {'hw': 610, 'hh': 3.5, 'rng': 3.0, 'sr': 4.0, 'nr': 2.0, 'ts': -12, 'tn': 25, 'hs': -0.4, 'hn': 0.1}, [617, 3.35])], [('secondary port differences {"hw": 300, "hh": 2.2, "rng": 0.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 300, 'hh': 2.2, 'rng': 0.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [320, 2.0]), ('secondary port differences {"hw": 1425, "hh": 4.0, "rng": 1.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1425, 'hh': 4.0, 'rng': 1.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 3.8]), ('secondary port differences {"hw": 30, "hh": 4.9, "rng": 4.7, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 30, 'hh': 4.9, 'rng': 4.7, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [1435, 4.3]), ('secondary port differences {"hw": 600, "hh": 4.0, "rng": 3.0, "sr": 4.0, "nr": 2.0, "ts": -35, "tn": 20, "hs": -0.5, "hn": -0.1}', {'hw': 600, 'hh': 4.0, 'rng': 3.0, 'sr': 4.0, 'nr': 2.0, 'ts': -35, 'tn': 20, 'hs': -0.5, 'hn': -0.1}, [593, 3.7]), ('secondary port differences {"hw": 610, "hh": 3.5, "rng": 3.0, "sr": 4.0, "nr": 2.0, "ts": -12, "tn": 25, "hs": -0.4, "hn": 0.1}', {'hw': 610, 'hh': 3.5, 'rng': 3.0, 'sr': 4.0, 'nr': 2.0, 'ts': -12, 'tn': 25, 'hs': -0.4, 'hn': 0.1}, [617, 3.35]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 1.8, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 1.8, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [620, 3.9]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 2.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [611, 3.83])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
secondary port differences {"hw": 20, "hh": 3.0, "rng": 1.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[54, 2.9][40, 2.8]Failed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 1.8, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[620, 3.9][620, 3.9]Passed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[611, 3.83][611, 3.83]Passed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.4, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[606, 3.8][606, 3.8]Passed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[593, 3.7][593, 3.7]Passed
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, 3.68][590, 3.68]Passed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.6, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[579, 3.6][579, 3.6]Passed

SHA-256 / 67f389963df7e7570931eefbf09236c6dc3305bb34c4a11d7f344d64fdde145c

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    k=(x['rng']-x['nr'])/(x['sr']-x['nr'])
    k=min(1.0,k)
    dt=x['tn']+(x['ts']-x['tn'])*k
    dh=x['hn']+(x['hs']-x['hn'])*k
    t=math.floor(x['hw']+dt+0.5)
    t=t%1440
    return [t,round(x['hh']+dh,2)]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('secondary port differences {"hw": 20, "hh": 3.0, "rng": 1.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 20, 'hh': 3.0, 'rng': 1.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [40, 2.8]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 1.8, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 1.8, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [620, 3.9]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 2.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [611, 3.83]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.4, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 2.4, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [606, 3.8]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 3.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [593, 3.7]), ('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}', {'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, 3.68]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.6, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 3.6, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [579, 3.6])], [('secondary port differences {"hw": 700, "hh": 5.0, "rng": 5.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 700, 'hh': 5.0, 'rng': 5.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [665, 4.4]), ('secondary port differences {"hw": 1425, "hh": 4.0, "rng": 1.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1425, 'hh': 4.0, 'rng': 1.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 3.8]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 3.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [593, 3.7]), ('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}', {'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, 3.68]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.6, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 3.6, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [579, 3.6]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 4.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 4.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [565, 3.5]), ('secondary port differences {"hw": 10, "hh": 3.8, "rng": 3.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 10, 'hh': 3.8, 'rng': 3.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [1422, 3.25])], [('secondary port differences {"hw": 1425, "hh": 4.0, "rng": 1.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1425, 'hh': 4.0, 'rng': 1.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 3.8]), ('secondary port differences {"hw": 300, "hh": 2.2, "rng": 0.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 300, 'hh': 2.2, 'rng': 0.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [320, 2.0]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 4.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 4.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [565, 3.5]), ('secondary port differences {"hw": 10, "hh": 3.8, "rng": 3.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 10, 'hh': 3.8, 'rng': 3.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [1422, 3.25]), ('secondary port differences {"hw": 1430, "hh": 4.4, "rng": 2.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1430, 'hh': 4.4, 'rng': 2.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 4.17]), ('secondary port differences {"hw": 20, "hh": 3.0, "rng": 1.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 20, 'hh': 3.0, 'rng': 1.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [40, 2.8]), ('secondary port differences {"hw": 700, "hh": 5.0, "rng": 5.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 700, 'hh': 5.0, 'rng': 5.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [665, 4.4])], [('secondary port differences {"hw": 30, "hh": 4.9, "rng": 4.7, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 30, 'hh': 4.9, 'rng': 4.7, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [1435, 4.3]), ('secondary port differences {"hw": 20, "hh": 3.0, "rng": 1.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 20, 'hh': 3.0, 'rng': 1.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [40, 2.8]), ('secondary port differences {"hw": 700, "hh": 5.0, "rng": 5.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 700, 'hh': 5.0, 'rng': 5.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [665, 4.4]), ('secondary port differences {"hw": 1425, "hh": 4.0, "rng": 1.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1425, 'hh': 4.0, 'rng': 1.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 3.8]), ('secondary port differences {"hw": 300, "hh": 2.2, "rng": 0.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 300, 'hh': 2.2, 'rng': 0.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [320, 2.0]), ('secondary port differences {"hw": 600, "hh": 4.0, "rng": 3.0, "sr": 4.0, "nr": 2.0, "ts": -35, "tn": 20, "hs": -0.5, "hn": -0.1}', {'hw': 600, 'hh': 4.0, 'rng': 3.0, 'sr': 4.0, 'nr': 2.0, 'ts': -35, 'tn': 20, 'hs': -0.5, 'hn': -0.1}, [593, 3.7]), ('secondary port differences {"hw": 610, "hh": 3.5, "rng": 3.0, "sr": 4.0, "nr": 2.0, "ts": -12, "tn": 25, "hs": -0.4, "hn": 0.1}', {'hw': 610, 'hh': 3.5, 'rng': 3.0, 'sr': 4.0, 'nr': 2.0, 'ts': -12, 'tn': 25, 'hs': -0.4, 'hn': 0.1}, [617, 3.35])], [('secondary port differences {"hw": 300, "hh": 2.2, "rng": 0.9, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 300, 'hh': 2.2, 'rng': 0.9, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [320, 2.0]), ('secondary port differences {"hw": 1425, "hh": 4.0, "rng": 1.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 1425, 'hh': 4.0, 'rng': 1.0, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [5, 3.8]), ('secondary port differences {"hw": 30, "hh": 4.9, "rng": 4.7, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 30, 'hh': 4.9, 'rng': 4.7, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [1435, 4.3]), ('secondary port differences {"hw": 600, "hh": 4.0, "rng": 3.0, "sr": 4.0, "nr": 2.0, "ts": -35, "tn": 20, "hs": -0.5, "hn": -0.1}', {'hw': 600, 'hh': 4.0, 'rng': 3.0, 'sr': 4.0, 'nr': 2.0, 'ts': -35, 'tn': 20, 'hs': -0.5, 'hn': -0.1}, [593, 3.7]), ('secondary port differences {"hw": 610, "hh": 3.5, "rng": 3.0, "sr": 4.0, "nr": 2.0, "ts": -12, "tn": 25, "hs": -0.4, "hn": 0.1}', {'hw': 610, 'hh': 3.5, 'rng': 3.0, 'sr': 4.0, 'nr': 2.0, 'ts': -12, 'tn': 25, 'hs': -0.4, 'hn': 0.1}, [617, 3.35]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 1.8, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 1.8, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [620, 3.9]), ('secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}', {'hw': 600, 'hh': 4.1, 'rng': 2.2, 'sr': 4.2, 'nr': 1.8, 'ts': -35, 'tn': 20, 'hs': -0.6, 'hn': -0.2}, [611, 3.83])]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
secondary port differences {"hw": 20, "hh": 3.0, "rng": 1.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[54, 2.9][40, 2.8]Failed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 1.8, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[620, 3.9][620, 3.9]Passed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.2, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[611, 3.83][611, 3.83]Passed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 2.4, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[606, 3.8][606, 3.8]Passed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.0, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[593, 3.7][593, 3.7]Passed
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, 3.68][590, 3.68]Passed
secondary port differences {"hw": 600, "hh": 4.1, "rng": 3.6, "sr": 4.2, "nr": 1.8, "ts": -35, "tn": 20, "hs": -0.6, "hn": -0.2}[579, 3.6][579, 3.6]Passed

SHA-256 / 48229fa4fa43d9e8409ab26df79b59ac5b94a89e682a510b0a8a653adc385de4

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 7 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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Verification & scope

A deterministic toy model with stipulated rules and constants; not certified hydrographic software or a substitute for official tide tables. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:48:06.722957+00:00.

Case digest / 2561098abbc961a82ae89d8723ec20aae1330858c92870319155ccdb75a45a50