FA-97827 / Knitting and sewing pattern grading / Member archive

Top-down sock fit calculator: stitch multiple rounding · case 02

A 2x2 rib sock casts on 58 stitches.

Member previewVariant 2 · 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
standard sock	`{"cast_on": 63, "flap_rows": 31, "heel_sts": 31, "pickup": 16}`	`{"cast_on": 64, "flap_rows": 32, "heel_sts": 32, "pickup": 17}`	Failed

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