FA-65488 / Ecological population dynamics / Member archive

Cohort life table statistics: generation time weighting · case 03

Generation time is one year too long.

Member previewVariant 3 · 3 implementations · 7 checks per implementation

Case contract

l0=1 and l[x+1]=l[x]*px[x]; R0=sum l[x]*mx[x]; generation time T=sum x*l[x]*mx[x]/R0; r=ln(R0)/T (None if T=0); e0 = sum over x of (l[x]+l[x+1])/2; return [R0, T, r, e0] rounded 6 with [0.0, None, None, e0] when R0=0; None for empty or mismatched schedules.

Why this case matters

Population projections set harvest quotas, conservation status and pest-control timing; a wrong update order, boundary or rate conversion silently changes management advice.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
regression: songbird	`[1.026, 2.77193, 0.00926, 1.115]`	`[1.026, 1.77193, 0.014486, 1.115]`	Failed

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