FA-97420 / Knitting and sewing pattern grading / Member archive

Yarn yardage estimator: metres per gram · case 05

A 50 g / 200 m fingering yarn is estimated to need fewer metres than grams.

Member previewVariant 5 · 3 implementations · 8 checks per implementation

Case contract

grams = garment_area / swatch_area * swatch_g; meters = grams * skein_m/skein_g; add margin_pct as a multiplier (meters*(1+margin/100)). skeins = ceiling(meters/skein_m); leftover = skeins*skein_m - meters. Return [meters, skeins, leftover] with meters and leftover half-up integers. Non-positive swatch area or skein weight -> "error: swatch".

Why this case matters

Designers and knitters estimate how many skeins to buy from a weighed swatch.

One recorded failure

Sample boundary fixture

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

Boundary fixture	Actual	Expected	Outcome
with margin	`[211, 2, 39]`	`[1320, 11, 55]`	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.