FA-69161 / Tide and marine navigation tables / Open access
Tidal coefficient classification: Only the preceding low water sets the range · case 01
Asymmetric tides get coefficients from one side of the high water.
ROOT CAUSE
The range is measured from the preceding low water only.
VERIFIED REPAIR
Use the mean of both flanking low waters.
Unsuccessful approach: Using the lower of the two low waters overstates the range.
Case contract
Input [hw, lw_before, lw_after, z0, U]: range = hw - mean of the two flanking low waters; coefficient = floor(100*(range/2)/U + 0.5) clamped to [20,120]. Class: exceptional if coef>=110, else spring if coef>=70, neap if coef<=45, else mean. Return [coef, class]. z0 (mean level) is informational only.
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):
hw,lb,la,z0,U=x
rng=hw-lb
c=math.floor(100*(rng/2)/U+0.5)
c=max(20,min(120,c))
if c>=110: cls='exceptional'
elif c>=70: cls='spring'
elif c<=45: cls='neap'
else: cls='mean'
return [c,cls]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('tidal coefficient classification [6.5, 0.9, 1.1, 3.6, 3.05]', [6.5, 0.9, 1.1, 3.6, 3.05], [90, 'spring']), ('tidal coefficient classification [5.2, 2.0, 2.1, 3.6, 3.05]', [5.2, 2.0, 2.1, 3.6, 3.05], [52, 'mean']), ('tidal coefficient classification [4.6, 2.6, 2.7, 3.6, 3.05]', [4.6, 2.6, 2.7, 3.6, 3.05], [32, 'neap']), ('tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05]', [7.4, 0.1, 0.3, 3.6, 3.05], [118, 'exceptional']), ('tidal coefficient classification [7.9, 0.0, 0.0, 3.6, 3.05]', [7.9, 0.0, 0.0, 3.6, 3.05], [120, 'exceptional']), ('tidal coefficient classification [3.9, 3.0, 3.1, 3.6, 3.05]', [3.9, 3.0, 3.1, 3.6, 3.05], [20, 'neap']), ('tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05]', [6.0, 1.73, 1.73, 3.6, 3.05], [70, 'spring'])], [('tidal coefficient classification [4.6, 2.6, 2.7, 3.6, 3.05]', [4.6, 2.6, 2.7, 3.6, 3.05], [32, 'neap']), ('tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05]', [7.4, 0.1, 0.3, 3.6, 3.05], [118, 'exceptional']), ('tidal coefficient classification [7.9, 0.0, 0.0, 3.6, 3.05]', [7.9, 0.0, 0.0, 3.6, 3.05], [120, 'exceptional']), ('tidal coefficient classification [3.9, 3.0, 3.1, 3.6, 3.05]', [3.9, 3.0, 3.1, 3.6, 3.05], [20, 'neap']), ('tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05]', [6.0, 1.73, 1.73, 3.6, 3.05], [70, 'spring']), ('tidal coefficient classification [5.0, 2.255, 2.255, 3.6, 3.05]', [5.0, 2.255, 2.255, 3.6, 3.05], [45, 'neap']), ('tidal coefficient classification [5.0, 2.25, 2.25, 3.6, 3.05]', [5.0, 2.25, 2.25, 3.6, 3.05], [45, 'neap'])], [('tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05]', [7.4, 0.1, 0.3, 3.6, 3.05], [118, 'exceptional']), ('tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05]', [6.0, 1.73, 1.73, 3.6, 3.05], [70, 'spring']), ('tidal coefficient classification [5.0, 2.255, 2.255, 3.6, 3.05]', [5.0, 2.255, 2.255, 3.6, 3.05], [45, 'neap']), ('tidal coefficient classification [5.0, 2.25, 2.25, 3.6, 3.05]', [5.0, 2.25, 2.25, 3.6, 3.05], [45, 'neap']), ('tidal coefficient classification [6.1, 1.3, 0.7, 3.6, 3.05]', [6.1, 1.3, 0.7, 3.6, 3.05], [84, 'spring']), ('tidal coefficient classification [6.3, 0.8, 1.6, 3.8, 3.05]', [6.3, 0.8, 1.6, 3.8, 3.05], [84, 'spring']), ('tidal coefficient classification [4.0, 1.0, 1.0, 2.4, 2.0]', [4.0, 1.0, 1.0, 2.4, 2.0], [75, 'spring'])], [('tidal coefficient classification [6.1, 1.3, 0.7, 3.6, 3.05]', [6.1, 1.3, 0.7, 3.6, 3.05], [84, 'spring']), ('tidal coefficient classification [6.3, 0.8, 1.6, 3.8, 3.05]', [6.3, 0.8, 1.6, 3.8, 3.05], [84, 'spring']), ('tidal coefficient classification [4.0, 1.0, 1.0, 2.4, 2.0]', [4.0, 1.0, 1.0, 2.4, 2.0], [75, 'spring']), ('tidal coefficient classification [4.4, 1.6, 1.6, 2.9, 2.0]', [4.4, 1.6, 1.6, 2.9, 2.0], [70, 'spring']), ('tidal coefficient classification [3.8, 0.0, 2.0, 2.1, 2.0]', [3.8, 0.0, 2.0, 2.1, 2.0], [70, 'spring']), ('tidal coefficient classification [5.0, 1.46, 1.46, 3.2, 2.0]', [5.0, 1.46, 1.46, 3.2, 2.0], [89, 'spring']), ('tidal coefficient classification [5.0, 1.22, 1.22, 3.2, 2.0]', [5.0, 1.22, 1.22, 3.2, 2.0], [95, 'spring'])], [('tidal coefficient classification [6.3, 0.8, 1.6, 3.8, 3.05]', [6.3, 0.8, 1.6, 3.8, 3.05], [84, 'spring']), ('tidal coefficient classification [4.4, 1.6, 1.6, 2.9, 2.0]', [4.4, 1.6, 1.6, 2.9, 2.0], [70, 'spring']), ('tidal coefficient classification [3.8, 0.0, 2.0, 2.1, 2.0]', [3.8, 0.0, 2.0, 2.1, 2.0], [70, 'spring']), ('tidal coefficient classification [5.0, 1.46, 1.46, 3.2, 2.0]', [5.0, 1.46, 1.46, 3.2, 2.0], [89, 'spring']), ('tidal coefficient classification [5.0, 1.22, 1.22, 3.2, 2.0]', [5.0, 1.22, 1.22, 3.2, 2.0], [95, 'spring']), ('tidal coefficient classification [5.4, 1.0, 1.0, 3.2, 2.0]', [5.4, 1.0, 1.0, 3.2, 2.0], [110, 'exceptional']), ('tidal coefficient classification [5.6, 0.9, 0.9, 3.2, 2.0]', [5.6, 0.9, 0.9, 3.2, 2.0], [117, 'exceptional'])]]
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| tidal coefficient classification [6.5, 0.9, 1.1, 3.6, 3.05] | [92, 'spring'] | [90, 'spring'] | Failed |
| tidal coefficient classification [5.2, 2.0, 2.1, 3.6, 3.05] | [52, 'mean'] | [52, 'mean'] | Passed |
| tidal coefficient classification [4.6, 2.6, 2.7, 3.6, 3.05] | [33, 'neap'] | [32, 'neap'] | Failed |
| tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05] | [120, 'exceptional'] | [118, 'exceptional'] | Failed |
| tidal coefficient classification [7.9, 0.0, 0.0, 3.6, 3.05] | [120, 'exceptional'] | [120, 'exceptional'] | Passed |
| tidal coefficient classification [3.9, 3.0, 3.1, 3.6, 3.05] | [20, 'neap'] | [20, 'neap'] | Passed |
| tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05] | [70, 'spring'] | [70, 'spring'] | Passed |
SHA-256 / ce49571da9195ceda32c0828dcb7fb3857ca840fc637dbd8abb6f5846d872a7a
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
hw,lb,la,z0,U=x
rng=hw-min(lb,la)
c=math.floor(100*(rng/2)/U+0.5)
c=max(20,min(120,c))
if c>=110: cls='exceptional'
elif c>=70: cls='spring'
elif c<=45: cls='neap'
else: cls='mean'
return [c,cls]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('tidal coefficient classification [6.5, 0.9, 1.1, 3.6, 3.05]', [6.5, 0.9, 1.1, 3.6, 3.05], [90, 'spring']), ('tidal coefficient classification [5.2, 2.0, 2.1, 3.6, 3.05]', [5.2, 2.0, 2.1, 3.6, 3.05], [52, 'mean']), ('tidal coefficient classification [4.6, 2.6, 2.7, 3.6, 3.05]', [4.6, 2.6, 2.7, 3.6, 3.05], [32, 'neap']), ('tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05]', [7.4, 0.1, 0.3, 3.6, 3.05], [118, 'exceptional']), ('tidal coefficient classification [7.9, 0.0, 0.0, 3.6, 3.05]', [7.9, 0.0, 0.0, 3.6, 3.05], [120, 'exceptional']), ('tidal coefficient classification [3.9, 3.0, 3.1, 3.6, 3.05]', [3.9, 3.0, 3.1, 3.6, 3.05], [20, 'neap']), ('tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05]', [6.0, 1.73, 1.73, 3.6, 3.05], [70, 'spring'])], [('tidal coefficient classification [4.6, 2.6, 2.7, 3.6, 3.05]', [4.6, 2.6, 2.7, 3.6, 3.05], [32, 'neap']), ('tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05]', [7.4, 0.1, 0.3, 3.6, 3.05], [118, 'exceptional']), ('tidal coefficient classification [7.9, 0.0, 0.0, 3.6, 3.05]', [7.9, 0.0, 0.0, 3.6, 3.05], [120, 'exceptional']), ('tidal coefficient classification [3.9, 3.0, 3.1, 3.6, 3.05]', [3.9, 3.0, 3.1, 3.6, 3.05], [20, 'neap']), ('tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05]', [6.0, 1.73, 1.73, 3.6, 3.05], [70, 'spring']), ('tidal coefficient classification [5.0, 2.255, 2.255, 3.6, 3.05]', [5.0, 2.255, 2.255, 3.6, 3.05], [45, 'neap']), ('tidal coefficient classification [5.0, 2.25, 2.25, 3.6, 3.05]', [5.0, 2.25, 2.25, 3.6, 3.05], [45, 'neap'])], [('tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05]', [7.4, 0.1, 0.3, 3.6, 3.05], [118, 'exceptional']), ('tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05]', [6.0, 1.73, 1.73, 3.6, 3.05], [70, 'spring']), ('tidal coefficient classification [5.0, 2.255, 2.255, 3.6, 3.05]', [5.0, 2.255, 2.255, 3.6, 3.05], [45, 'neap']), ('tidal coefficient classification [5.0, 2.25, 2.25, 3.6, 3.05]', [5.0, 2.25, 2.25, 3.6, 3.05], [45, 'neap']), ('tidal coefficient classification [6.1, 1.3, 0.7, 3.6, 3.05]', [6.1, 1.3, 0.7, 3.6, 3.05], [84, 'spring']), ('tidal coefficient classification [6.3, 0.8, 1.6, 3.8, 3.05]', [6.3, 0.8, 1.6, 3.8, 3.05], [84, 'spring']), ('tidal coefficient classification [4.0, 1.0, 1.0, 2.4, 2.0]', [4.0, 1.0, 1.0, 2.4, 2.0], [75, 'spring'])], [('tidal coefficient classification [6.1, 1.3, 0.7, 3.6, 3.05]', [6.1, 1.3, 0.7, 3.6, 3.05], [84, 'spring']), ('tidal coefficient classification [6.3, 0.8, 1.6, 3.8, 3.05]', [6.3, 0.8, 1.6, 3.8, 3.05], [84, 'spring']), ('tidal coefficient classification [4.0, 1.0, 1.0, 2.4, 2.0]', [4.0, 1.0, 1.0, 2.4, 2.0], [75, 'spring']), ('tidal coefficient classification [4.4, 1.6, 1.6, 2.9, 2.0]', [4.4, 1.6, 1.6, 2.9, 2.0], [70, 'spring']), ('tidal coefficient classification [3.8, 0.0, 2.0, 2.1, 2.0]', [3.8, 0.0, 2.0, 2.1, 2.0], [70, 'spring']), ('tidal coefficient classification [5.0, 1.46, 1.46, 3.2, 2.0]', [5.0, 1.46, 1.46, 3.2, 2.0], [89, 'spring']), ('tidal coefficient classification [5.0, 1.22, 1.22, 3.2, 2.0]', [5.0, 1.22, 1.22, 3.2, 2.0], [95, 'spring'])], [('tidal coefficient classification [6.3, 0.8, 1.6, 3.8, 3.05]', [6.3, 0.8, 1.6, 3.8, 3.05], [84, 'spring']), ('tidal coefficient classification [4.4, 1.6, 1.6, 2.9, 2.0]', [4.4, 1.6, 1.6, 2.9, 2.0], [70, 'spring']), ('tidal coefficient classification [3.8, 0.0, 2.0, 2.1, 2.0]', [3.8, 0.0, 2.0, 2.1, 2.0], [70, 'spring']), ('tidal coefficient classification [5.0, 1.46, 1.46, 3.2, 2.0]', [5.0, 1.46, 1.46, 3.2, 2.0], [89, 'spring']), ('tidal coefficient classification [5.0, 1.22, 1.22, 3.2, 2.0]', [5.0, 1.22, 1.22, 3.2, 2.0], [95, 'spring']), ('tidal coefficient classification [5.4, 1.0, 1.0, 3.2, 2.0]', [5.4, 1.0, 1.0, 3.2, 2.0], [110, 'exceptional']), ('tidal coefficient classification [5.6, 0.9, 0.9, 3.2, 2.0]', [5.6, 0.9, 0.9, 3.2, 2.0], [117, 'exceptional'])]]
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| tidal coefficient classification [6.5, 0.9, 1.1, 3.6, 3.05] | [92, 'spring'] | [90, 'spring'] | Failed |
| tidal coefficient classification [5.2, 2.0, 2.1, 3.6, 3.05] | [52, 'mean'] | [52, 'mean'] | Passed |
| tidal coefficient classification [4.6, 2.6, 2.7, 3.6, 3.05] | [33, 'neap'] | [32, 'neap'] | Failed |
| tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05] | [120, 'exceptional'] | [118, 'exceptional'] | Failed |
| tidal coefficient classification [7.9, 0.0, 0.0, 3.6, 3.05] | [120, 'exceptional'] | [120, 'exceptional'] | Passed |
| tidal coefficient classification [3.9, 3.0, 3.1, 3.6, 3.05] | [20, 'neap'] | [20, 'neap'] | Passed |
| tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05] | [70, 'spring'] | [70, 'spring'] | Passed |
SHA-256 / 9ba51a1b017a4a3320292fac3a0219a63ed58ad3bb426f8032c726a3c16a0b33
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
hw,lb,la,z0,U=x
rng=hw-(lb+la)/2
c=math.floor(100*(rng/2)/U+0.5)
c=max(20,min(120,c))
if c>=110: cls='exceptional'
elif c>=70: cls='spring'
elif c<=45: cls='neap'
else: cls='mean'
return [c,cls]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('tidal coefficient classification [6.5, 0.9, 1.1, 3.6, 3.05]', [6.5, 0.9, 1.1, 3.6, 3.05], [90, 'spring']), ('tidal coefficient classification [5.2, 2.0, 2.1, 3.6, 3.05]', [5.2, 2.0, 2.1, 3.6, 3.05], [52, 'mean']), ('tidal coefficient classification [4.6, 2.6, 2.7, 3.6, 3.05]', [4.6, 2.6, 2.7, 3.6, 3.05], [32, 'neap']), ('tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05]', [7.4, 0.1, 0.3, 3.6, 3.05], [118, 'exceptional']), ('tidal coefficient classification [7.9, 0.0, 0.0, 3.6, 3.05]', [7.9, 0.0, 0.0, 3.6, 3.05], [120, 'exceptional']), ('tidal coefficient classification [3.9, 3.0, 3.1, 3.6, 3.05]', [3.9, 3.0, 3.1, 3.6, 3.05], [20, 'neap']), ('tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05]', [6.0, 1.73, 1.73, 3.6, 3.05], [70, 'spring'])], [('tidal coefficient classification [4.6, 2.6, 2.7, 3.6, 3.05]', [4.6, 2.6, 2.7, 3.6, 3.05], [32, 'neap']), ('tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05]', [7.4, 0.1, 0.3, 3.6, 3.05], [118, 'exceptional']), ('tidal coefficient classification [7.9, 0.0, 0.0, 3.6, 3.05]', [7.9, 0.0, 0.0, 3.6, 3.05], [120, 'exceptional']), ('tidal coefficient classification [3.9, 3.0, 3.1, 3.6, 3.05]', [3.9, 3.0, 3.1, 3.6, 3.05], [20, 'neap']), ('tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05]', [6.0, 1.73, 1.73, 3.6, 3.05], [70, 'spring']), ('tidal coefficient classification [5.0, 2.255, 2.255, 3.6, 3.05]', [5.0, 2.255, 2.255, 3.6, 3.05], [45, 'neap']), ('tidal coefficient classification [5.0, 2.25, 2.25, 3.6, 3.05]', [5.0, 2.25, 2.25, 3.6, 3.05], [45, 'neap'])], [('tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05]', [7.4, 0.1, 0.3, 3.6, 3.05], [118, 'exceptional']), ('tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05]', [6.0, 1.73, 1.73, 3.6, 3.05], [70, 'spring']), ('tidal coefficient classification [5.0, 2.255, 2.255, 3.6, 3.05]', [5.0, 2.255, 2.255, 3.6, 3.05], [45, 'neap']), ('tidal coefficient classification [5.0, 2.25, 2.25, 3.6, 3.05]', [5.0, 2.25, 2.25, 3.6, 3.05], [45, 'neap']), ('tidal coefficient classification [6.1, 1.3, 0.7, 3.6, 3.05]', [6.1, 1.3, 0.7, 3.6, 3.05], [84, 'spring']), ('tidal coefficient classification [6.3, 0.8, 1.6, 3.8, 3.05]', [6.3, 0.8, 1.6, 3.8, 3.05], [84, 'spring']), ('tidal coefficient classification [4.0, 1.0, 1.0, 2.4, 2.0]', [4.0, 1.0, 1.0, 2.4, 2.0], [75, 'spring'])], [('tidal coefficient classification [6.1, 1.3, 0.7, 3.6, 3.05]', [6.1, 1.3, 0.7, 3.6, 3.05], [84, 'spring']), ('tidal coefficient classification [6.3, 0.8, 1.6, 3.8, 3.05]', [6.3, 0.8, 1.6, 3.8, 3.05], [84, 'spring']), ('tidal coefficient classification [4.0, 1.0, 1.0, 2.4, 2.0]', [4.0, 1.0, 1.0, 2.4, 2.0], [75, 'spring']), ('tidal coefficient classification [4.4, 1.6, 1.6, 2.9, 2.0]', [4.4, 1.6, 1.6, 2.9, 2.0], [70, 'spring']), ('tidal coefficient classification [3.8, 0.0, 2.0, 2.1, 2.0]', [3.8, 0.0, 2.0, 2.1, 2.0], [70, 'spring']), ('tidal coefficient classification [5.0, 1.46, 1.46, 3.2, 2.0]', [5.0, 1.46, 1.46, 3.2, 2.0], [89, 'spring']), ('tidal coefficient classification [5.0, 1.22, 1.22, 3.2, 2.0]', [5.0, 1.22, 1.22, 3.2, 2.0], [95, 'spring'])], [('tidal coefficient classification [6.3, 0.8, 1.6, 3.8, 3.05]', [6.3, 0.8, 1.6, 3.8, 3.05], [84, 'spring']), ('tidal coefficient classification [4.4, 1.6, 1.6, 2.9, 2.0]', [4.4, 1.6, 1.6, 2.9, 2.0], [70, 'spring']), ('tidal coefficient classification [3.8, 0.0, 2.0, 2.1, 2.0]', [3.8, 0.0, 2.0, 2.1, 2.0], [70, 'spring']), ('tidal coefficient classification [5.0, 1.46, 1.46, 3.2, 2.0]', [5.0, 1.46, 1.46, 3.2, 2.0], [89, 'spring']), ('tidal coefficient classification [5.0, 1.22, 1.22, 3.2, 2.0]', [5.0, 1.22, 1.22, 3.2, 2.0], [95, 'spring']), ('tidal coefficient classification [5.4, 1.0, 1.0, 3.2, 2.0]', [5.4, 1.0, 1.0, 3.2, 2.0], [110, 'exceptional']), ('tidal coefficient classification [5.6, 0.9, 0.9, 3.2, 2.0]', [5.6, 0.9, 0.9, 3.2, 2.0], [117, 'exceptional'])]]
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| tidal coefficient classification [6.5, 0.9, 1.1, 3.6, 3.05] | [90, 'spring'] | [90, 'spring'] | Passed |
| tidal coefficient classification [5.2, 2.0, 2.1, 3.6, 3.05] | [52, 'mean'] | [52, 'mean'] | Passed |
| tidal coefficient classification [4.6, 2.6, 2.7, 3.6, 3.05] | [32, 'neap'] | [32, 'neap'] | Passed |
| tidal coefficient classification [7.4, 0.1, 0.3, 3.6, 3.05] | [118, 'exceptional'] | [118, 'exceptional'] | Passed |
| tidal coefficient classification [7.9, 0.0, 0.0, 3.6, 3.05] | [120, 'exceptional'] | [120, 'exceptional'] | Passed |
| tidal coefficient classification [3.9, 3.0, 3.1, 3.6, 3.05] | [20, 'neap'] | [20, 'neap'] | Passed |
| tidal coefficient classification [6.0, 1.73, 1.73, 3.6, 3.05] | [70, 'spring'] | [70, 'spring'] | Passed |
SHA-256 / 9fc8b7c9196392ab9602aa44c80cf29a62d6816e6ce1313716389ba70f2127a2
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 2026-09-29T14:48:08.865247+00:00.
Case digest / 07649feb854a4308447c90c835f791f613630ed9cfca5e61e4a43e905227a5a8