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Troubleshooting

Common mistakes and how to fix them.

Map renders as an empty grey circle

Cause: Die coordinates from a CSV parser are strings, not numbers. The library matches data to the die grid by integer position — string "5" does not match integer 5, so no dies get filled.

Fix: Cast every numeric field with + or Number() before passing to buildWaferMap:

buildWaferMap({
  results: rows.map(r => ({
    x:    +r.x,
    y:    +r.y,
    hbin: +r.hbin,
    testValues: { 1010: +r.testA },
  })),
});

How to confirm: check result.dataCoverage.filledDies. If it is 0 with non-empty input, coordinates are not matching.

Yield shows 0 % or 100 % when it should not

Cause: passBins defaults to [1], but your test program uses a different bin for pass (e.g. bin 0, or multiple bins).

Fix: pass the correct passBins everywhere it matters — buildWaferMap, analyzeWaferMap, and renderWaferMap:

const PASS = [1, 2]; // your actual passing bins

const result  = buildWaferMap({ results, passBins: PASS });
const summary = analyzeWaferMap(result, { passBins: PASS });

renderWaferMap(container, result, {
  passBins: PASS,        // summary panel yield label
  statsSummary: summary,
});

How to confirm: result.yield.passDies and result.yield.failDies reflect whatever passBins was passed to buildWaferMap. If the numbers look wrong, check that value first.

Stacked plot modes missing from the toolbar

Cause: stackedValues, stackedBins, and stackedSoftBins only appear in the toolbar when result.isLotStack is true. This flag is only set when lotStack was passed to buildWaferMap — it is not set when you call aggregateValues manually and feed the result to a single-wafer buildWaferMap.

Fix: use the lotStack input:

// Correct — toolbar shows stacked modes
const result = buildWaferMap({
  lotStack: {
    results: [wafer1Rows, wafer2Rows, wafer3Rows],
    method:  'mean',
  },
  waferConfig: { diameter: 300 },
  dieConfig:   { width: 10, height: 10 },
});

window is not defined or document is not defined on the server

Cause: renderWaferMap (and toCanvas) require a browser DOM. They will throw if called during SSR in Next.js, Nuxt, SvelteKit, or Remix.

Fix: gate the renderer inside the browser lifecycle. buildWaferMap and analyzeWaferMap are pure functions with no DOM dependency — only the renderer call needs to be deferred.

=== React === 

useEffect(() => {
  const ctrl = renderWaferMap(ref.current, result);
  return () => ctrl.destroy();
}, [result]);

=== Vue === 

onMounted(() => {
  ctrl = renderWaferMap(el.value, result);
});

=== SvelteKit === 

onMount(() => {
  ctrl = renderWaferMap(host, result);
});

=== Next.js ===

Use a dynamic import with ssr: false, or guard with typeof window !== 'undefined' inside a useEffect.

Further reading