FA-97833 / Knitting and sewing pattern grading / Member archive

Top-down sock fit calculator: heel flap share · case 03

Heel flaps are a third of the sock.

Member previewVariant 3 · 3 implementations · 8 checks per implementation

Case contract

Leg stitches = foot_circ*(1 - neg_ease/100)*gauge/10 rounded to the nearest multiple of `multiple` (half-up). Heel flap = half the stitches; flap rows = heel stitches; gusset pick-up per side = flap rows/2 + 1. Return {cast_on, heel_sts, flap_rows, pickup}.

Why this case matters

Sock patterns size with negative ease and derive heel flap and gusset counts.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
wide foot	`{"cast_on": 80, "flap_rows": 26, "heel_sts": 26, "pickup": 14}`	`{"cast_on": 80, "flap_rows": 40, "heel_sts": 40, "pickup": 21}`	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.