Developer Guide — wafermap¶

For: developers integrating the library. Read first: Quick Start. If you're an engineer using an app built with wafermap, you want the Application User Guide instead.

This guide walks through building wafer map visualisations in a real application, from a single interactive map up to a multi-wafer gallery with statistical findings. It focuses on practical patterns; for the full type reference see API Reference. For a visual overview of how the library fits together, see Architecture.

How to read this guide. Sections 1–6 are the core path — read them in order to go from install to a map coloured by bins or test values. Everything after that is a topic jump: pick the section for the feature you need (§10 findings, §12 gallery, §14 Insights, §17 worker, …). Each feature section ends with a → Demo link to a live example page showing the same feature as working code.

Architecture at a glance¶

If you are trying to understand the shape of the library before choosing an API, start with Architecture. It shows the top-level flow from raw wafer data to built maps, rendered views, analysis summaries, and worker-based execution.

1. Installation and setup¶

Install the package:

npm install @wafertools/wafermap

The preferred canvas renderers have no external dependencies.

With a bundler (Vite, webpack, etc.)¶

import { buildWaferMap } from '@wafertools/wafermap';
import { renderWaferMap } from '@wafertools/wafermap/render';
import { analyzeWaferMap } from '@wafertools/wafermap/stats';

Plain HTML (CDN / script tags)¶

<script type="module">
  import { buildWaferMap } from 'https://esm.sh/@wafertools/wafermap';
  import { renderWaferMap, renderWaferGallery } from 'https://esm.sh/@wafertools/wafermap/render';
</script>

2. Your first wafer map¶

The minimal path is two function calls: buildWaferMap to process your data, then renderWaferMap to draw it.

renderWaferMap creates and manages its own <canvas> — pass any block element sized to the desired display area:

<!-- Fixed size: -->
<div id="map" style="width:500px; height:500px;"></div>

<!-- Responsive square (fills its container, always square): -->
<div id="map" style="width:100%; aspect-ratio:1;"></div>

import { buildWaferMap } from '@wafertools/wafermap';
import { renderWaferMap } from '@wafertools/wafermap/render';

// Minimum input: x/y die grid positions. The library infers everything else.
const result = buildWaferMap([
  { x:  0, y:  0, hbin: 1 },
  { x:  1, y:  0, hbin: 2 },
  { x:  0, y: -1, hbin: 1 },
  { x:  1, y: -1, hbin: 1 },
  // ... more dies
]);

renderWaferMap(document.getElementById('map'), result);

To respond to die clicks, pass an onClick callback — the Die object has x, y, hbin, sbin, and testValues:

renderWaferMap(document.getElementById('map'), result, {
  onClick: (die) => console.log(die.x, die.y, die.hbin),
});

renderWaferMap returns immediately and mounts a self-contained interactive map. A toolbar is always shown (top-right), giving users access to all display controls — no extra HTML or JavaScript required (showToolbar defaults to true). The toolbar includes an expand button (⛶) that opens the map in an enlarged modal overlay without rebuilding the view.

x and y are always die grid positions (prober step coordinates) — integers like −7, 0, 5. They are NOT millimetre values. The library converts to physical mm internally when you supply a die size.

→ Demo: Your first wafer map

3. Loading real data from a CSV¶

In practice your data comes from a wafer prober log, STDF export, or a CSV pulled from your database. A typical row has a wafer ID, die grid position, and one or more test results.

lot,wafer,x,y,hbin,sbin,testA,testB,testC
LOT123,W01,-7,-2,3,45,1.098,0.773,5.758
LOT123,W01,-7,-1,1,10,1.099,0.772,5.966
...

Parse the CSV and map each row to a DieResult. All numeric fields must be cast to number — CSV parsers return strings. buildWaferMap will throw a descriptive error if it detects string x/y coordinates, but other fields such as hbin and testValues values must also be cast to avoid silent NaN artefacts.

import { buildWaferMap } from '@wafertools/wafermap';
import { renderWaferMap } from '@wafertools/wafermap/render';

async function loadAndRender(csvText: string, container: HTMLElement) {
  const rows = parseCsv(csvText);  // your CSV parser of choice

  const results = rows.map(r => ({
    x:          Number(r.x),       // must be number — not string "3"
    y:          Number(r.y),
    hbin:       Number(r.hbin),
    sbin:       Number(r.sbin),
    testValues: { 1010: Number(r.testA), 1020: Number(r.testB), 1030: Number(r.testC) },
  }));

  const result = buildWaferMap({
    results,
    testDefs: [
      { testNumber: 1010, name: 'TestA' },
      { testNumber: 1020, name: 'TestB' },
      { testNumber: 1030, name: 'TestC' },
    ],
  });
  renderWaferMap(container, result);
}

x and y are the prober step positions from your equipment — pass them directly, no unit conversion needed.

→ Demo: Loading real data from a CSV

Here we have toggled some toolbar options on: XY Axis indicator and Ring boundaries.

For a real-world dataset, see Demo: Real wafer defect data (WM-811K), which loads a sample from the WM-811K public dataset and lets you explore the spatial findings engine across known defect pattern types (Center, Donut, Edge-Loc, Scratch, etc.).

4. Adding die size and wafer geometry¶

When you supply physical dimensions, die.physX and die.physY are in millimetres and the wafer boundary is drawn to scale; die.x/die.y remain die grid positions (prober step coordinates).

const result = buildWaferMap({
  results,
  waferConfig: {
    diameter:  300,                       // mm — 200 or 300 are most common
    notch:     { type: 'bottom' },        // physical alignment notch direction
  },
  dieConfig: {
    width:  10,                           // mm — die X pitch
    height: 10,                           // mm — die Y pitch
  },
});

The notch renders as a V-notch on 200 mm+ wafers and as a flat on smaller wafers — you don't need to specify which.

When you don't know the geometry¶

Omit any field you don't know — the library infers what it can:

// Die size known, diameter unknown → diameter inferred from grid extent
buildWaferMap({ results, dieConfig: { width: 10, height: 10 } });

// Diameter known, die size unknown → die size estimated from diameter ÷ grid extent
buildWaferMap({ results, waferConfig: { diameter: 300 } });

// Nothing known → proportionally correct layout in normalised units
buildWaferMap({ results });

Check result.units to know which case applied: 'mm' means physical millimetres; 'normalized' means grid-relative units.

Partial data — anchoring the wafer centre¶

Inference reads geometry from how far your data reaches. That works as long as the data reaches the true wafer edge — including sparse data, where positions are missing across the whole face (systematic skip-sampling such as 1-in-4, or random sampling). Sparse data still resolves the diameter and centre correctly with no hints.

It breaks for partial data — a contiguous region that stops short of the edge: a half wafer, a single quadrant, a slice, or an off-centre cluster. The extent understates the wafer, so the region is mistaken for a smaller full wafer and re-centred on its own midpoint. For partial data, give the library the true diameter and the prober coordinate of the wafer centre:

// Only the right half of a 300 mm wafer was tested; prober (0,0) is the centre.
const result = buildWaferMap({
  results,
  waferConfig: { diameter: 300, center: { x: 0, y: 0 } },
  dieConfig:   { width: 10, height: 10 },
});

waferConfig.center anchors placement to the real centre. It does not change the public die.x/die.y labels — those stay the original prober coordinates.

When the library detects likely-partial coverage with no center, it adds a structured WaferWarning to result.warnings (code 'partial-coverage') and sets result.inference.wafer.method to 'inferred-partial'. Detection is heuristic, so for any partial dataset set waferConfig.center explicitly rather than relying on the warning. (result.inference.warnings is a deprecated string-array mirror of the same messages — use result.warnings in new code.)

Edge exclusion¶

const result = buildWaferMap({
  results,
  waferConfig: { diameter: 300, edgeExclusion: 3 },  // 3 mm exclusion band
  dieConfig:   { width: 10, height: 10 },
});

console.log(result.yield.yieldPercent);  // excludes edge dies from numerator and denominator

Dies within the exclusion band have die.edgeExcluded = true and are shown dimmed on the map.

Coordinate origins¶

If your prober uses a non-centred origin, tell the library:

// All x,y ≥ 0 → auto-detected as lower-left origin (no explicit config needed)
buildWaferMap({ results, dieConfig: { width: 10, height: 10 } });

// Row-based prober: origin at upper-left, Y increases downward
buildWaferMap({
  results,
  dieConfig: { width: 10, height: 10, coordinateOrigin: { type: 'UL' } },
});

→ Demo: Die size and wafer geometry

→ Demo: Partial data

5. Working with bins¶

Bins are the primary pass/fail classification from wafer test equipment. Hard bins are the physical sort result; soft bins are the failure category assigned by the test program.

Basic bin map¶

const results = rows.map(r => ({
  x:    Number(r.x),
  y:    Number(r.y),
  hbin: Number(r.hbin),
}));

const result = buildWaferMap({ results });
renderWaferMap(container, result);
// Opens in 'hardBin' mode by default

Named bins with custom colours¶

Without names, bins are labelled "HBin 1", "HBin 2", etc. Supply hbinDefs for readable labels and optional colour overrides:

const result = buildWaferMap({
  results,
  hbinDefs: [
    { bin: 1, name: 'Pass',          color: '#2ecc71' },
    { bin: 2, name: 'Contact Open',  color: '#e74c3c' },
    { bin: 3, name: 'Vth - Hi NMOS', color: '#e67e22' },
    { bin: 5, name: 'Continuity',    color: '#9b59b6' },
  ],
});

renderWaferMap(container, result, {
  viewOptions: { plotMode: 'hardBin' },
});

Tip: Pass hbinDefs into buildWaferMap, not just renderWaferMap. The stats engine and tooltips both read them from the built result.

Hard bin and soft bin together¶

const results = rows.map(r => ({
  x:    Number(r.x),
  y:    Number(r.y),
  hbin: Number(r.hbin),
  sbin: Number(r.sbin),
}));

const result = buildWaferMap({
  results,
  hbinDefs: [ { bin: 1, name: 'Pass' }, /* ... */ ],
  sbinDefs: [ { bin: 10, name: 'Vth - Lo' }, { bin: 11, name: 'Vth - Hi' }, /* ... */ ],
});

renderWaferMap(container, result);
// hbinDefs and sbinDefs are inherited automatically from the result
// User can switch between Hard Bin and Soft Bin in the toolbar Mode menu

Pass bins and yield¶

The library counts yield against passBins (default [1]). Change this if your pass bin isn't 1:

const result = buildWaferMap({
  results,
  passBins: [1, 100],   // bins 1 and 100 are both counted as pass
});

const yld = result.yield.yieldPercent;
console.log(yld !== null ? `${yld.toFixed(1)}%` : 'n/a');

→ Demo: Working with bins

6. Working with test values¶

Three related terms appear together throughout the API — here is how they fit:

The integer key in testValues and testDef.testNumber must match exactly — the library uses these to link measurements to names and to drive the stats engine.

Continuous test measurements (leakage current, threshold voltage, etc.) go in testValues — a map keyed by a stable integer test identity. TestDef is optional: without it the library uses Test {N} (the testNumber) everywhere a name would appear — mode dropdown, tooltip, colorbar axis, summary panel. Add TestDef when you want human-readable names, units, and SI prefix formatting:

const results = rows.map(r => ({
  x:          Number(r.x),
  y:          Number(r.y),
  testValues: {
    1050: Number(r.idsat),
    1060: Number(r.vth),
    1070: Number(r.ioff),
  },
}));

const result = buildWaferMap({
  results,
  dieConfig: { width: 8, height: 12 },
  testDefs: [
    { testNumber: 1050, name: 'Idsat', unit: 'A' },
    { testNumber: 1060, name: 'Vth',   unit: 'V' },
    { testNumber: 1070, name: 'Ioff',  unit: 'A' },
  ],
});

renderWaferMap(container, result, {
  viewOptions: {
    plotMode:   'value',
    activeTest: 1050,   // testNumber for Idsat — NOT a positional index
    // testDefs inherited automatically from the result
  },
});

The testValues key is any stable integer that uniquely identifies the test — for example an STDF TEST_NUM, a database test ID, or an application-defined constant. The key must match the testNumber field in the corresponding TestDef.

Always pass the SI base unit in TestDef.unit (e.g. 'A', 'V', 'Ω', 'F'). The formatter applies SI prefixes automatically — 0.03 with unit 'Ω' displays as 30 mΩ. Passing a pre-scaled unit like 'mA' would produce incorrect labels (e.g. 30 µmA instead of 30 nA).

With testDefs in place: - The toolbar Mode dropdown shows one entry per test by name ("Idsat", "Vth", …) — without testDefs it shows "Test 1050", "Test 1060", etc. - Hover tooltips show "Idsat: 1.23 mA" — without testDefs they show "Test 1050: 1.23 mA" - The colorbar axis label includes the name and unit — without testDefs it shows "Test 1050" - The summary panel Test Values section uses test names — without testDefs it uses "Test 1050", etc.

TestDef.logScale: true enables log₁₀ scale for that test by default (silently falls back to linear when any die value ≤ 0). The user can also toggle log scale at any time via the toolbar Log scale button, which overrides the per-test default.

Spec limits on test parameters¶

Add limitLow and/or limitHigh to a TestDef to specify the engineering specification window. Both are optional independently — one-sided limits are valid. Once limits are defined, two things happen automatically across all plot modes:

In value mode — spec limits affect both the colorbar and the die colours:

The colorbar always shows LSL / USL labels at the limit positions. Exactly how depends on the colorbar range mode (toggled via the bracket toolbar button):

colorbarRangeMode controls only the colorbar's numeric range — not how out-of-spec dies are shown:

• colorbarRangeMode: 'spec' (default when limits are present) — the bar spans [limitLow, limitHigh]. The limit values appear as "LSL" / "USL" labels at the bar endpoints alongside the numeric values.
• colorbarRangeMode: 'data' — the bar spans the actual data min/max. LSL / USL are shown as marker lines on the bar wherever the limits fall within the data range.

In both ranges, all dies are coloured by the gradient so the value distribution stays readable and the bar and die colours agree; out-of-spec dies additionally carry a triangle marker — ▽ (below limitLow) / △ (above limitHigh), each tagged with a matching key beside the LSL / USL labels — so they remain flagged without dropping out of the distribution. The triangle is drawn black or white per die for contrast against its own gradient fill, so it stays visible under any colour scheme, and its shape (not colour) carries the below/above-limit meaning — readable even in greyscale or with colour-vision deficiency.

With passFailDisplay: 'spec' — a categorical pass/fail view instead of the continuous gradient, judged against the spec limits: - Pass (in spec): green (#2ecc71) - Fail low (below LSL): blue (#3498db) - Fail high (above USL): red (#e74c3c) - No data: grey

In this mode the colorbar is replaced by a spec legend showing the categories that apply (Pass always; Fail high / Fail low only when the test defines that limit) with per-category die counts. The title reads {test} · #{number} above the legend and Spec pass/fail below it.

const testDefs = [
  { testNumber: 1050, name: 'Idsat', unit: 'A' },
  {
    testNumber: 1060, name: 'Vth', unit: 'V',
    limitLow:  0.44,  // LSL — below this is a spec failure
    limitHigh: 0.57,  // USL — above this is a spec failure
  },
  { testNumber: 1070, name: 'Ioff', unit: 'A' },
];

const result = buildWaferMap({ results, waferConfig, dieConfig, testDefs });

// Enable pass/fail colouring for Vth to see spec status at a glance
renderWaferMap(container, result, {
  viewOptions: {
    plotMode:        'value',
    passFailDisplay: 'spec',
    activeTest:      1060,
    // testDefs inherited automatically from the result
  },
});

Spec limits also feed the stats engine: analyzeWaferMap populates summary.stats.testSpecYield with per-test spec yield, fail-low count, and fail-high count for every test that has at least one limit defined.

→ Demo: Working with test values

The same map with the view option 'Spec pass/fail' selected. Now the map shows the dies in spec limits in green and the dies out of limits in red, for the given test.

Functional tests (pass/fail only, no measured value)¶

Not every test produces a number. A continuity check, a boundary-scan pass, or any go/no-go test has only an outcome — set testType: 'F' on that test's TestDef (default is 'P', parametric) and record the verdict on the die in testPass, keyed by testNumber the same way testValues is:

const testDefs = [
  { testNumber: 1050, name: 'Idsat', unit: 'A' },
  { testNumber: 1080, name: 'Continuity', testType: 'F' },  // no unit, no limits — verdict only
];

const results = [
  { x: 0, y: 0, hbin: 1, testValues: { 1050: 1.42e-3 }, testPass: { 1080: true } },
  { x: 1, y: 0, hbin: 2, testValues: { 1050: 1.38e-3 }, testPass: { 1080: false } },
  // ...
];

const result = buildWaferMap({ results, testDefs, passBins: [1] });

Selecting a functional test as the active test always renders as Test pass/fail (passFailDisplay: 'test') — coloured by the tester's recorded verdict from die.testPass, green pass / red fail, undirected (there is no "which side" the way spec limits have a high/low side). This is forced regardless of the requested display; a functional test has nothing to put on a gradient. The Overlays menu's "Test pass/fail" toggle is also available on a parametric test that happens to carry recorded verdicts (e.g. a tester-recorded PTR TEST_FLG), as an alternative to spec-limit judgement.

Functional tests are excluded from every parametric statistic — per-test stats, capability, correlation, distribution charts, value stacks, and regional value findings — since a mean or Cpk of a binary outcome is meaningless. They get their own pass-rate analysis instead: stats.functionalYield (one entry per functional test, with passDies/failDies/totalDies/passRatePercent), a Functional Tests table in the summary panel (§11) alongside — not replacing — the parametric Test values table, and regional pass-rate findings (kind: 'functionalTest').

Legacy encoding. If your data predates testPass and encodes a functional outcome as a testValues entry of 1 (pass) / 0 (fail), that keeps working — getTestPassStatus(die, testNumber, testDef) is the single read-path for verdicts everywhere in the library (rendering, stats, findings) and falls back to that encoding for a functional test with no testPass entry. New code should write testPass and leave functional tests out of testValues entirely.

7. Retests and enriching dies after build¶

Handling retests¶

If your data includes multiple probe results for the same die position (retests), the library handles them automatically. Four policies are available:

const result = buildWaferMap({
  results:      rawResults,  // may contain the same (x,y) more than once
  retestPolicy: 'best',      // keep the best bin result per position
});

// Check which dies were retested:
result.dies.filter(d => d.retestCount !== undefined)
           .forEach(d => console.log(`(${d.x},${d.y}) retested ${d.retestCount}×`));

Retested dies automatically show "Retests: N" in their hover tooltip. retestCount is only set on dies that appeared more than once in the input — non-retested dies have retestCount === undefined.

Post-enrichment (attaching extra values after the map is built)¶

Sometimes you need to attach data that isn't in the same table as the grid positions — for example, merging test values from a separate parametric table into a map already built from a bin summary:

import { buildWaferMap, getDieKey } from '@wafertools/wafermap';

// Step 1: build the map from the bin data
const result = buildWaferMap({ results: binRows.map(r => ({
  x: Number(r.x), y: Number(r.y), hbin: Number(r.hbin),
})), dieConfig: { width: 10, height: 10 } });

// Step 2: build a lookup from the parametric table
const paramMap = new Map(paramRows.map(r => [getDieKey({ x: Number(r.x), y: Number(r.y) }), r]));

// Step 3: enrich dies in place
const enrichedDies = result.dies.map(die => {
  const row = paramMap.get(getDieKey(die));
  if (!row) return die;
  return { ...die, testValues: { 1050: Number(row.idsat), 1060: Number(row.vth) } };
});

// testDefs must be on the result so the stats engine and tooltips can read them
const testDefs = [
  { testNumber: 1050, name: 'Idsat', unit: 'A' },
  { testNumber: 1060, name: 'Vth',   unit: 'V' },
];

renderWaferMap(container, { ...result, dies: enrichedDies, testDefs });

Always use getDieKey(die) for lookups rather than manually formatting "${die.x},${die.y}" — it guarantees the correct format after any grid offset correction.

Wafer vs. per-die metadata¶

Lot- and wafer-level facts — lot, product, test program, temperature, test date — belong on WaferMetadata, passed once via waferConfig.metadata. A die cannot differ from its wafer on these, so they live on the wafer and the tooltip reads them from there:

const result = buildWaferMap({
  results: rows.map(r => ({ x: Number(r.x), y: Number(r.y), hbin: Number(r.hbin) })),
  waferConfig: {
    metadata: { lot: 'LOT-001', product: 'NMOS-A', testProgram: 'NM_v3.2', temperature: 25 },
  },
  dieConfig: { width: 10, height: 10 },
});

Use the metadata field on a DieResult only for data that genuinely varies die-to-die — any key is accepted via the open index signature and shown in the tooltip:

results: rows.map(r => ({
  x: Number(r.x), y: Number(r.y), hbin: Number(r.hbin),
  metadata: { probeCard: r.probe_card, inkDate: r.ink_date },
})),

Metadata appears automatically in hover tooltips — no extra configuration. The tooltip merges the wafer's WaferMetadata (base) with the die's DieMetadata; a per-die key overrides the wafer value of the same name. null/undefined values are skipped. wmap renders whatever keys you supply, so you control tooltip content through the metadata you set.

Changed in 0.15.0: wafer-level fields (lotId, waferId, deviceType, testProgram, temperature) were removed from DieMetadata — set them on WaferMetadata instead. See the migration note in the changelog.

Read metadata back from the die in any callback:

renderWaferMap(container, result, {
  onClick: (die) => {
    console.log(die.metadata?.lotId);      // named field
    console.log(die.metadata?.probeCard);  // custom field
  },
});

Wafer-level metadata¶

Custom fields work the same way on waferConfig.metadata (WaferMetadata → §12.3). They appear in the summary panel header alongside the named fields:

const result = buildWaferMap({
  results: rows.map(r => ({ x: Number(r.x), y: Number(r.y), hbin: Number(r.hbin) })),
  dieConfig: { width: 10, height: 10 },
  waferConfig: {
    metadata: {
      lot:      'LOT123',
      waferId:  1,
      testDate: '2026-04-23',
      // custom fields — shown in summary panel header
      equipmentId: 'P-01',
      recipe:      'NMOS-R2',
    },
  },
});

→ Demo: Working with retested dies

8. Controlling the display¶

Initial display options¶

Pass viewOptions to renderWaferMap to set the initial state:

renderWaferMap(container, result, {
  viewOptions: {
    plotMode:                'hardBin',
    colorScheme:             'default',     // 'default', 'greyscale', 'accessible', 'plasma', 'inferno'
    showRingBoundaries:      true,
    showQuadrantBoundaries:  false,
    showDieLabels:           false,         // die index labels
    showXYIndicator:         true,
    ringCount:               4,
    rotation:                0,             // 0, 90, 180, 270
    flipX:                   false,
    flipY:                   false,
    legendPosition:             'default',     // 'default'|'compact'|'left'|'top'|'bottom'|'floating'
  },
});

All of these can also be changed by the user via the toolbar at any time.

Programmatic control¶

renderWaferMap returns a controller you can call from application code:

const ctrl = renderWaferMap(container, result, { viewOptions: { plotMode: 'hardBin' } });

// Switch display mode (activeTest is a testNumber, e.g. from testDefs):
ctrl.setOptions({ plotMode: 'value', activeTest: 1050 });

// Replace die data (e.g. after a data reload) — preserves zoom/pan:
ctrl.setDies(newDies);

// Read current state:
const opts = ctrl.getOptions();
console.log(opts.plotMode, opts.colorScheme);

// Return to default zoom:
ctrl.resetZoom();

// Clean up when the component unmounts:
ctrl.destroy();

Syncing with external UI controls¶

Use onViewOptionsChange to keep your own UI elements in sync with the toolbar:

const ctrl = renderWaferMap(container, result, {
  viewOptions: { plotMode: 'hardBin' },
  onViewOptionsChange: (opts) => {
    modeDropdown.value     = opts.plotMode;
    schemeDropdown.value   = opts.colorScheme;
    ringsCheckbox.checked  = opts.showRingBoundaries ?? false;
  },
});

// When your own control changes, push it back:
modeDropdown.addEventListener('change', () => {
  ctrl.setOptions({ plotMode: modeDropdown.value });
});

onViewOptionsChange fires only when the toolbar changes options. Calling ctrl.setOptions() programmatically does NOT re-fire it, so there is no feedback loop.

Hiding the toolbar¶

If you want a static display with no toolbar:

renderWaferMap(container, result, {
  showToolbar: false,
  viewOptions: { plotMode: 'hardBin' },
});

Or keep the toolbar but remove the mode selector (useful when your app manages the mode externally):

renderWaferMap(container, result, {
  showPlotModeSelector: false,
  viewOptions: { plotMode: 'value' },
  onViewOptionsChange: (opts) => syncMyModeUI(opts),
});

Bin legend position¶

In hardBin and softBin modes, the bin legend can be placed in six positions via the Legend style toolbar button or the legendPosition option:

Set the initial position via viewOptions — the user can change it at any time via the toolbar:

renderWaferMap(container, result, {
  viewOptions: { plotMode: 'hardBin', legendPosition: 'floating' },
});

The Legend style button is automatically disabled when the map is in value or stacked mode, since those modes use a continuous colorbar instead of a bin legend.

For galleries, legendPosition is a top-level GalleryOptions field and applies to all cards:

renderWaferGallery(container, items, {
  legendPosition: 'floating',
});

Toolbar reference¶

The toolbar is always shown — at the top-right of a single map, or as a persistent bar above the gallery grid. Which buttons appear depends on the context and the current data.

Single map toolbar¶

	Button	Condition	What it does
	Download PNG	Always	Saves the current canvas at current zoom/rotation
	Zoom mode	Always	Drag to zoom into a region
	Zoom in / Zoom out / Reset	Always	Step zoom; Reset returns to fitted view
	Pan mode	Always	Drag to pan
	Box select	Always	Drag to select a group of dies; fires onSelect when provided
	Plot mode	Unless showPlotModeSelector: false	Opens mode menu: Test Value, Hard Bin, Soft Bin, and Stacked modes (only when map was built with lotStack)
	Colour palette	Always	Opens colour scheme picker
	Log scale	Value / stacked-values mode only	Toggles log₁₀ colour normalisation; disabled when min ≤ 0; hidden whenever a solid pass/fail display is active or the active test is functional (log scale has no effect on pass/fail colouring)
	Colorbar range	Value mode, test has limitLow or limitHigh, pass/fail display off	Toggles the colorbar's numeric range between spec-limit range ([limitLow, limitHigh]) and data range (actual min/max). Out-of-spec dies are flagged with ▽/△ markers in both.
	Overlays	Always	Dropdown: Ring boundaries, Quadrant lines, Die labels, Reticle grid (when reticles present), XY indicator, Spec pass/fail (value mode, test has limits), Test pass/fail (value mode, active test is functional or has recorded verdicts)
	Legend style	Hard bin or soft bin mode only	Dropdown: legend position (default, compact, left, top, bottom, floating)
	Orientation	Always	Dropdown: Rotate 90° CW, Flip horizontal, Flip vertical
	Summary	Only when statsSummary is provided	Toggles the Summary panel (metadata, yield, bins, ring/quadrant, test values, findings)
	Insights	Only when insights: { enabled: true }	Swaps the map for this wafer's own chart suite — see §14
	Expand	Unless showExpandButton: false	Opens the map in an enlarged modal overlay; canvas reparented — no view rebuild. A maximise button in the modal grows it to fill the window (F). E key shortcut (also disabled when showExpandButton: false). Hidden (and E disabled) while the Insights tab is open — see below.
	User guide	Only when showHelpButton: true	Opens the built-in end-user guide — a real, separate window when available, falling back to an in-page non-modal floating window when window.open is blocked (some embedded WebViews). Callable directly via openUserGuide() regardless of showHelpButton. userGuideExtension inserts a host app's own documentation into it, see API reference

The full toolbar is shown when toolbarControls is 'full' (default). A gallery card's detached window also uses 'full'. In the gallery, cards show only the navigation controls (download, zoom, pan, select) — the view controls (mode, overlays, orient, etc.) live in the shared gallery bar.

While the Insights tab is open, every button above except Insights and User guide is hidden — none of the others (download, zoom/pan/select, mode, palette, overlays, legend, orientation, Expand) apply to the chart suite underneath, and Findings specifically toggles the map's own findings panel, which sits behind the Insights tab's opaque overlay with no visible effect while it's open. Expand is hidden rather than repurposed: each chart panel inside Insights has its own expand button for enlarging that one chart instead.

Gallery control bar¶

The gallery control bar is always visible above the card grid.

	Button	Condition	What it does
	Plot mode	Unless showPlotModeSelector: false	Same mode menu as single map; stacked modes always available in the gallery
	Colour palette	Always	Colour scheme picker; applies to all cards
	Aggregation method	Stacked Test Values mode only	Selects mean, median, std dev, min, max, or count; re-aggregates all cards immediately
	Log scale	Value / stacked-values mode only	Applies to all cards
	Colorbar range	Value mode, active test has limitLow or limitHigh, pass/fail display off	Toggles the colorbar's numeric range: spec-limit range ↔ data range. Out-of-spec dies are flagged with ▽/△ markers in both; applies to all cards
	Overlays	Always	Dropdown: Ring boundaries, Quadrant lines, Die labels, Reticle grid (when any card has reticles), XY indicator, Spec pass/fail (value mode, active test has limits), Test pass/fail (value mode, active test is functional or has recorded verdicts) — applies to all cards
	Legend style	Hard bin or soft bin mode only	Dropdown: legend position; applies to all cards
	Orientation	Always	Dropdown: Rotate 90° CW, Flip horizontal, Flip vertical — applies to all cards
	Columns	Always	Dropdown: fix the column count to 1–5, or choose Auto to let the gallery size columns based on die pitch. Cards are size-capped and pack from the left rather than stretching to fill the width
	Download all	Always	Exports all cards as a single tiled PNG
	Lot findings	Only when lotStatsSummary is provided	Toggles the lot-level summary and findings panel
	Insights	Only when insights: { enabled: true }	Swaps the grid for a lot-wide chart suite — see §14
	User guide	Only when showHelpButton: true	Opens the built-in end-user guide — a real, separate window when available, falling back to an in-page non-modal floating window when window.open is blocked (some embedded WebViews). Callable directly via openUserGuide() regardless of showHelpButton. userGuideExtension inserts a host app's own documentation into it, see API reference

While the Insights tab is open, every button above except Insights and User guide is hidden — none of the others (mode, palette, overlays, columns, download, etc.) apply to the chart suite underneath, and Lot findings specifically toggles the summary panel inside the grid body, which is already hidden while the Insights tab is showing.

Theming the chrome¶

wmap's chrome — the toolbar, gallery cards, summary panel, menus, tooltip — and the wafer canvas (background, axis labels, grid) are themed through --wmap-* CSS custom properties. Set them on any ancestor of the render container and everything wmap draws follows. Every token has a light default, so you override only what differs; a host that sets nothing gets the default light appearance.

/* The Nord theme shown above — set on a wrapper around the render container */
.my-nord-wrap {
  --wmap-canvas-bg:   #2e3440;   /* the wafer canvas */
  --wmap-surface:     #323846;   /* cards, menus, toolbar */
  --wmap-panel-bg:    #2b303b;   /* summary panel */
  --wmap-border:      #434c5e;
  --wmap-text:        #e5e9f0;
  --wmap-text-muted:  #a6adbb;
  --wmap-icon:        #d8dee9;
  --wmap-icon-hover:  #88c0d0;   /* accent — hover/active affordances */
  --wmap-icon-active: #88c0d0;
  --wmap-selected:    #88c0d0;   /* finding-drilldown card outline */
  /* …see the full token table in the API reference… */
}

To follow the OS preference, put the light values on :root and override in a @media (prefers-color-scheme: dark) block. Canvas colours are re-resolved on a theme change or light/dark flip, so the wafer repaints to match.

The data palette (the bin/value colours of the dies) is separate — it's controlled by colorScheme (see §18), not these tokens, and does not follow the chrome accent.

→ Demo: Theming with --wmap-* tokens · full token reference in the API docs

9. Responding to user interaction¶

Click and hover callbacks¶

renderWaferMap(container, result, {
  onClick: (die, event) => {
    console.log(`Clicked die (${die.x}, ${die.y})`);
    console.log('Hard bin:', die.hbin);
    console.log('Test values:', die.testValues);
    showDetailPanel(die);
  },
  onHover: (die, event) => {
    if (die) updateStatusBar(`(${die.x}, ${die.y})`);
    else     clearStatusBar();
  },
});

onClick and onHover receive the full Die object — die.x, die.y, die.testValues, die.hbin, die.sbin, and any metadata you attached. onHover receives null when the cursor leaves a die.

Box selection¶

The box-select button is always in the toolbar. Provide onSelect to receive the selected dies when the user finishes a drag selection:

renderWaferMap(container, result, {
  onSelect: (selectedDies) => {
    console.log(`${selectedDies.length} dies selected`);
    const passing = selectedDies.filter(d => d.hbin === 1).length;
    showSelectionStats({ count: selectedDies.length, passing });
  },
});

Users can also click individual dies, Ctrl/Cmd+click to add to the selection, and press Esc to clear.

Programmatic selection¶

// Highlight a specific set of dies (e.g. from a table click):
const failingDies = result.dies.filter(d => d.hbin === 2);
ctrl.setSelection(failingDies);

// Clear:
ctrl.clearSelection();

Bin legend filter¶

In hardBin and softBin modes, clicking any row in the bin legend dims all dies that do not belong to that bin — making it easy to isolate a single failure category across the wafer. Click the same row again to clear the filter.

// Equivalent programmatic control:
ctrl.setOptions({ highlightBin: 2 });   // isolate bin 2
ctrl.setOptions({ highlightBin: undefined }); // clear

The filter also works in gallery view — clicking a legend row in the gallery toolbar highlights that bin across every card simultaneously.

10. Adding statistical findings¶

The statistics engine (analyzeWaferMap) scans for spatial patterns across five families: rings, quadrants, angular sectors, contiguous failure clusters, and edge arcs. For each family it compares the local zone to the rest of the wafer using a statistical test appropriate to the variable type.

It also runs a spatial pattern classifier that labels the overall failure signature of the wafer — edge-ring, center cluster, scratch, and so on. This operates separately from the zone-by-zone statistical tests: the statistical findings are the evidence, the pattern label is the interpretation. See Spatial Pattern Detection for how the classifier works, what it was tested on, and its known limitations.

Basic usage¶

Pass the result of analyzeWaferMap to renderWaferMap as statsSummary. That's all most users need — the library handles the rest.

import { buildWaferMap } from '@wafertools/wafermap';
import { renderWaferMap } from '@wafertools/wafermap/render';
import { analyzeWaferMap } from '@wafertools/wafermap/stats';  // note: /stats subpath, not root

const result  = buildWaferMap({ results, waferConfig, dieConfig, passBins: [1] });
const summary = analyzeWaferMap(result);   // passBins inferred from result — no need to repeat it

renderWaferMap(container, result, {
  statsSummary: summary,
});

A "Findings" button (notebook icon) appears in the toolbar. Clicking it opens the summary panel — a persistent results panel alongside the map showing yield, bin distribution, ring and quadrant stats, test value summaries, and the full findings list. Clicking any finding in the panel highlights the affected dies on the map. See §11 Summary panel for the full panel content reference and configuration options (auto-open, pinned placement, gallery use).

When you pass a WaferMapResult to analyzeWaferMap, the passBins you gave to buildWaferMap are carried through automatically — you only need to set passBins explicitly in analyzeWaferMap options if you want to override them.

What gets analysed¶

By default the engine checks every combination of:

• Ring zones — each concentric ring vs. the rest of the wafer
• Quadrant zones — each of NE/NW/SE/SW vs. the rest of the wafer
• Angular sectors — 16 compass-direction sectors (N, NNE, NE, …) vs. the rest of the wafer; finer directional resolution than quadrants, catching drift patterns a single quadrant would dilute
• Reticle-field positions — each reticle cell vs. other cells (only when a reticleConfig was used)
• Failure clusters — contiguous groups of failing dies that are denser than the wafer-wide background failure rate; each cluster highlighted as a specific set of dies
• Edge arcs — failure clusters whose centroid is near the wafer perimeter and whose angular span is narrow; distinguished from full-ring edge effects (which ring analysis catches separately)

For each spatial family the engine tests: yield, hard bin rate per bin, soft bin rate per bin, and mean test value per test.

Angular sectors in detail. Sector analysis divides the wafer into compass-named angular slices — N, NNE, NE, ENE, E, … (16 sectors by default). Each sector is compared to the rest of the wafer independently, giving finer directional resolution than quadrants: a drift pattern concentrated in the NE corner shows up as a sector finding even if the wider NE quadrant is diluted by clean dies elsewhere in that quarter. Dies within 0.2 normalised radius of the wafer centre are excluded from sector analysis (they are too close to the centre to be meaningfully attributed to a direction). The number of sectors is controlled by sectorCount (4, 8, 16, or 32); the feature can be disabled entirely with enableAngularAnalysis: false.

Findings are suppressed unless they pass both an adjusted p-value threshold and an effect size gate. The effect size gate uses two complementary criteria — absolute and relative — so that meaningful patterns are not missed on wafers with either high or low background failure rates.

Clicking a finding highlights the map¶

When the user clicks a finding row in the panel, the map automatically: 1. Switches to the most relevant display mode (value mode for test findings, bin mode for bin findings) 2. Highlights the affected die zone with an amber overlay

Clicking the finding again clears the highlight.

Interpreting findings and severity¶

The findings list is ranked and filtered by statistical strength and effect size:

• p-value correction: adjusted p-values are used (default significanceLevel = 0.05), corrected per-family using a Benjamini–Hochberg FDR procedure.
• Effect size gate for yield/bin/cluster findings: a finding passes if it satisfies at least one of:
• absolute |delta| ≥ minimumEffectSize (default 0.15, i.e. a 15 percentage-point difference), or
• relative |delta / background| ≥ minimumRelativeEffect (default 0.5, i.e. 50% above or below the wafer-wide background rate)

The relative criterion matters on low-failure-rate wafers. With a 2% background rate, a 2 percentage-point elevation is only 0.02 in absolute terms (below the 0.15 threshold) but represents a 100% relative deviation — clearly significant. Without the relative criterion that finding would be silently dropped.

• Effect size for test-value findings: Cohen's d (pooled SD). Only minimumEffectSize applies; relative effect is not used for continuous measurements.
• Minimum sample size per region is auto-scaled to roughly 1% of wafer die count (minimum 5). Regions smaller than this are not tested.

Severity is derived from the adjusted p-value and the strongest satisfied effect criterion:

Cluster and edge-arc findings have an additional size criterion applied after the rate-based gate above. A large contiguous cluster is intrinsically striking even when the background failure rate is elevated (e.g. a 500-die donut ring that forms its own high background). The size thresholds are:

A cluster qualifies for a severity level if it satisfies either the rate criterion or the size criterion (both require the p-value gate).

Use the summary, effect, and stats fields on each StatsFinding to display numerical details to users.

Controlling what is analysed¶

const summary = analyzeWaferMap(result, {
  ringCount:                 4,      // must match the renderer's ringCount
  passBins:                  [1],
  significanceLevel:         0.05,   // adjusted p-value threshold
  minimumEffectSize:         0.15,   // min absolute |delta| for proportion findings
  minimumRelativeEffect:     0.5,    // min relative |delta / background| for proportion findings
                                     // a finding passes if it satisfies either this OR minimumEffectSize
  enableYieldAnalysis:       true,
  enableHardBinAnalysis:     true,
  enableSoftBinAnalysis:     true,
  enableTestValueAnalysis:   true,   // default FALSE — opt in for regional test-value findings (expensive);
                                     // use computePerTestStats: true for box-plot stats without the Welch pass
  enableReticlePositionAnalysis: true,  // auto-disabled when no reticle config
  enableAngularAnalysis:     true,   // sector directional analysis
  enableClusterAnalysis:     true,   // contiguous failure cluster + edge arc detection
  sectorCount:               8,      // 4 | 8 | 16 | 32
});

How the analysis is structured: variable × region¶

Regional analysis has two independent axes, and it helps to keep them separate:

• What is measured (the variable): yield, hard bin, soft bin, or test value.
• Where it is measured (the region family): rings, quadrants, sectors, reticle positions, or test sites.

Every enabled variable is compared across every enabled region family — they form a grid. Sectors, reticle positions, and test sites are not specific to any one variable: if reticle analysis is on, you get yield and bin and (when enabled) test-value findings broken down by reticle position, exactly as you do for rings.

The column toggles control which region families are built at all:

1. Sectors — built only when enableAngularAnalysis: true (default), with sectorCount slices.
2. Reticle positions — built only when enableReticlePositionAnalysis: true (default) and a reticle configuration is present; otherwise skipped automatically.
3. Test sites — built only when the wafer has meaningful site duplication (≥ 2 distinct siteNum values, each on ≥ 3 dies), unless enableTestSiteAnalysis forces it on (true) or off (false).

Rings and quadrants are always built. The row toggles control which variables are compared across whatever families exist.

Which test-value setting to use¶

The test-value row is off by default because it is the expensive one — it runs a Welch comparison for every test across every region, scaling with regions × tests × dies. Leaving it off costs you nothing on yield or bins; you lose only the parametric (measured-value) findings. Choose based on what you need:

enableTestValueAnalysis also produces the per-test descriptive stats, so you never need both. The cost multipliers are illustrative (measured at ~2.8k dies × 200 tests); the absolute numbers scale with your test count.

→ Demo: Summary panel uses computePerTestStats: true to populate the per-test value section of the panel.
See also: Demo: Standalone stacked map with spatial analysis, which uses enableTestValueAnalysis: true to surface regional test-value findings on a lot-averaged map.

Cluster and edge-arc highlights¶

Cluster and edge-arc findings use { kind: 'dies' } highlights — they identify the exact set of failing dies, not a region. Clicking one in the summary panel highlights those specific dies on the map:

const clusters = filterFindings(summary, { family: 'cluster' });
const arcs     = filterFindings(summary, { family: 'edge-arc' });
const sectors  = filterFindings(summary, { family: 'sector' });

// Each cluster finding's highlight carries the exact die keys:
for (const f of clusters) {
  console.log(f.comparison.left);    // e.g. "Cluster at (3, 2)"
  console.log(f.highlight.dieKeys);  // ['3,2', '4,2', '3,3', ...]
}

Reading findings in code¶

If you need to drive your own UI from findings rather than using the built-in panel, each finding is a StatsFinding with a human-readable summary and structured data:

for (const finding of summary.findings) {
  console.log(finding.severity);          // 'unusual' | 'notable' | 'info'
  console.log(finding.summary);           // "Ring 3 (edge) yield is lower than the rest of the wafer"
  console.log(finding.variable.kind);     // 'yield' | 'hardBin' | 'softBin' | 'test'
  console.log(finding.effect.absoluteDelta);  // signed magnitude of the effect
  console.log(finding.stats.adjustedPValue);  // BH-adjusted p-value
}

summary.findings is sorted by severity — 'unusual' first, then 'notable', then 'info'. findings[0] is always the highest-severity finding; no manual sort needed.

Updating findings after a data change¶

// After replacing die data:
ctrl.setDies(newDies);
const newSummary = analyzeWaferMap({ ...result, dies: newDies });
ctrl.setStatsSummary(newSummary);

A finding object in full:

{
  id:       'ring:Ring 4 (edge)',
  level:    'wafer',
  severity: 'unusual',            // 'unusual' > 'notable' > 'info'
  variable: { kind: 'yield', label: 'Yield' },
  comparison: { family: 'ring', left: 'Ring 4 (edge)', right: 'Rest of wafer' },
  effect:   { direction: 'lower', absoluteDelta: -0.18, relativeDelta: -0.62 },
  stats:    { method: 'z', pValue: 0.003, adjustedPValue: 0.009,
              sampleSizeLeft: 48, sampleSizeRight: 412 },
  summary:  'Ring 4 (edge) yield is lower than the rest of the wafer',
  highlight: { kind: 'region', regionFamily: 'ring', regionKeys: ['ring:4'], dieKeys: ['6,0', '6,1', /* … */] },
}

Use finding.summary for display text. Use finding.highlight to programmatically select or colour dies associated with the finding.

For running the stats engine in Node.js without a browser, see the recipe in §19.

→ Demo: Statistical findings

11. Summary panel¶

The summary panel is a persistent results panel that sits alongside the wafer map. It shows yield, bin distribution, ring and quadrant statistics, test value summaries, and the full findings list — all in one place without requiring the user to open the toolbar findings button.

Adding a summary panel to a single map¶

Pass statsSummary to renderWaferMap and the Summary button appears in the toolbar automatically. The panel is hidden by default; clicking the button toggles it open:

import { buildWaferMap } from '@wafertools/wafermap';
import { renderWaferMap } from '@wafertools/wafermap/render';
import { analyzeWaferMap } from '@wafertools/wafermap/stats';

const result  = buildWaferMap({ results, waferConfig, dieConfig, passBins: [1] });
const summary = analyzeWaferMap(result);

renderWaferMap(container, result, {
  statsSummary: summary,
});

To start with the panel already open (no toolbar click required), add summaryPanel: { defaultOpen: true }:

renderWaferMap(container, result, {
  statsSummary: summary,
  summaryPanel: { defaultOpen: true },
});

The toolbar Summary button reflects the current open/closed state, and the user can still toggle the panel closed via that button. Combine with a placement to pin the panel to a specific side of the canvas without the toggle behaviour:

renderWaferMap(container, result, {
  statsSummary: summary,
  summaryPanel: { placement: 'right' },   // always visible; no toggle
});

What the panel shows¶

The panel is divided into sections:

Updating the panel after data changes¶

const ctrl = renderWaferMap(container, result, { statsSummary: summary });

// After a data reload:
ctrl.setDies(newDies);
const newSummary = analyzeWaferMap({ ...result, dies: newDies });
ctrl.setStatsSummary(newSummary);

Summary panel in a gallery¶

For a gallery, call analyzeWaferLot and pass the result as lotStatsSummary — that's all you need. analyzeWaferLot runs per-wafer analysis internally, so the result contains complete findings for every wafer. A "Summary" button appears in the control bar giving access to:

• Lot tab — cross-wafer patterns and yield outliers
• Wafers tab — per-wafer findings index; clicking any row detaches that wafer's card into its own window with its summary panel

See §13 Lot-level statistical findings for the full example.

If you are building a gallery without lot-level analysis — for example, a set of unrelated wafers — you can attach statsSummary to each item individually:

const items = waferResults.map((r, i) => ({
  ...r,
  label:        `Wafer ${i + 1}`,
  statsSummary: analyzeWaferMap(r),
}));

renderWaferGallery(container, items);
// → Wafers tab of the Summary panel appears in toolbar
// → Each card's own window shows its own per-wafer summary

→ Demo: Summary panel

12. Building a lot gallery¶

renderWaferGallery renders multiple wafer maps in a responsive card grid. All cards share a single control bar — changing mode, colour, rotate, or flip applies to every card at once.

The gallery container needs a width but not a fixed height — the grid grows to fit its cards automatically. width: 100% is the typical choice:

<div id="gallery" style="width: 100%;"></div>

Basic gallery¶

import { buildWaferMap } from '@wafertools/wafermap';
import { renderWaferGallery } from '@wafertools/wafermap/render';

// Build a result per wafer
const waferResults = waferDatasets.map(data =>
  buildWaferMap({
    results:     data.map(r => ({ x: +r.x, y: +r.y, hbin: +r.hbin, sbin: +r.sbin })),
    waferConfig: { diameter: 300, notch: { type: 'bottom' } },
    dieConfig:   { width: 10, height: 10 },
    hbinDefs,
    sbinDefs,
  })
);

// Build gallery items
const items = waferResults.map((r, i) => ({
  ...r,
  label: `Wafer ${i + 1}`,
}));

const ctrl = renderWaferGallery(
  document.getElementById('gallery'),
  items,
  { viewOptions: { plotMode: 'hardBin' } },
);

Cards reflow responsively as the container resizes. Each card has an expand button (↗) in its header — clicking it detaches that card into its own real, separate window (not an in-page overlay), so it can be moved anywhere on screen, including outside the host app's own window. The gallery grid stays fully interactive the whole time, and any number of cards can be detached at once. See §6.6 Detaching a card into its own window in the API reference for reattach, multi-window, and embedded-host (Tauri/Electron) details.

Sharing bin and test definitions across cards¶

Pass hbinDefs, sbinDefs, and testDefs to buildWaferMap — they are stored on each WaferMapResult and flow automatically to the gallery's shared legend and tooltips:

const waferResults = waferDatasets.map(data =>
  buildWaferMap({
    results: data.map(r => ({ x: +r.x, y: +r.y, hbin: +r.hbin, sbin: +r.sbin })),
    hbinDefs: [
      { bin: 1, name: 'Pass',  color: '#2ecc71' },
      { bin: 2, name: 'Fail',  color: '#e74c3c' },
    ],
    sbinDefs: [
      { bin: 10, name: 'Vth - Lo' },
      { bin: 11, name: 'Vth - Hi' },
    ],
    testDefs: [
      { testNumber: 1050, name: 'Idsat', unit: 'A' },
      { testNumber: 1060, name: 'Vth',   unit: 'V' },
    ],
  })
);

renderWaferGallery(container, items, { viewOptions: { plotMode: 'hardBin' } });

Per-card overrides¶

Each WaferMapDisplayItem can override any viewOptions field. The per-card value is merged on top of the shared options. Use this sparingly — the main purpose is providing per-card reticle geometry:

const items = waferResults.map((r, i) => ({
  ...r,
  label: `Wafer ${i + 1}`,
  // r.reticles is already on the item via the spread — the gallery enables
  // the Reticle toolbar button automatically when any item has reticles
}));

Click and select callbacks¶

const items = waferResults.map((r, i) => ({
  ...r,
  label: `W${i + 1}`,
  onClick:  (die) => showDieDetail(die, i),
  onSelect: (dies) => showSelectionPanel(i, dies),
}));

Updating the gallery after data changes¶

// Rebuild after the user changes wafer selection:
ctrl.setItems(newItems);

// Sync display mode from an external control:
ctrl.setOptions({ plotMode: 'value', activeTest: 1050 });

// Track state changes back to your UI:
renderWaferGallery(container, items, {
  onViewOptionsChange: (opts) => {
    myModeDropdown.value = opts.plotMode;
  },
});

Stacked lot maps¶

The gallery toolbar includes three stacked modes that aggregate the full lot into a single view — one card per bin or per test parameter. Switch mode via the mode picker in the gallery control bar:

Switching to a stacked mode rebuilds the card set automatically; switching back restores the original per-wafer cards.

Aggregation method. For Stacked Test Values the default aggregation is mean. Change it via the Σ button in the gallery control bar (visible only in this mode), or programmatically:

ctrl.setOptions({ aggregationMethod: 'median' });  // re-aggregates immediately

Zero-config discovery. Even without testDefs or binDefs, the gallery scans the lot data to discover unique tests and bins when entering a stacked mode, and generates default labels (e.g. "Test 1050", "Bin 2") automatically.

Spatial findings. Each stacked card automatically gets a spatial analysis summary — detach the card into its own window and click the findings button to see ring, quadrant, sector, and cluster findings on the aggregated map. No extra code is required.

→ Demo: Building a lot gallery
See also: Demo: Lot-level findings with stacked modes

13. Lot-level statistical findings¶

analyzeWaferLot detects cross-wafer patterns across a lot:

• Repeated patterns — ring, quadrant, or reticle findings that appear on ≥ 2 wafers
• Inter-wafer yield outliers — individual wafers whose yield deviates from the lot median

It runs per-wafer analysis internally, so a single call gives you everything — no separate analyzeWaferMap per item is needed.

import { analyzeWaferLot } from '@wafertools/wafermap/stats';

const lotSummary = analyzeWaferLot(waferResults, { ringCount: 4 });

const items = waferResults.map((r, i) => ({
  ...r,
  label: `Wafer ${i + 1}`,
}));

renderWaferGallery(container, items, {
  viewOptions:     { plotMode: 'hardBin' },
  lotStatsSummary: lotSummary,
});

Pass computePerTestStats: true to also populate lotSummary.perWaferTestStats — a per-wafer × per-test five-number summary (min/Q1/median/Q3/max plus mean/stddev/count) ready for box-plot rendering. Each entry corresponds to one wafer and has a tests array with the same shape as StatsSummary.stats.perTestStats. (enableTestValueAnalysis: true populates it too, but also runs the much more expensive regional Welch findings pass — prefer computePerTestStats when you only need distribution stats for box plots.)

A "Findings" button appears in the gallery control bar. Clicking it opens a panel with two tabs:

• Lot — lot-level yield, bin breakdown, ring/quadrant statistics, cross-wafer findings
• Wafers — per-wafer findings index; click any wafer to detach its card into its own window with full per-wafer findings

What highlighting looks like¶

• Repeated pattern finding (ring/quadrant seen across N wafers): the affected wafer cards are outlined; the matching die zone is highlighted on each card using that wafer's own per-wafer finding data
• Yield outlier (single wafer): the outlier card is outlined
• Clicking the active finding again clears all highlights

Updating the lot summary at runtime¶

const ctrl = renderWaferGallery(container, items, { lotStatsSummary });

// After data changes:
const newLotSummary = analyzeWaferLot(newResults);
ctrl.setLotStatsSummary(newLotSummary);

→ Demo: Lot-level statistical findings

Exporting reports¶

The library can generate standalone printable HTML reports that open in a new browser tab and can be saved as PDF.

Wafer summary report — everything shown in a single wafer's summary panel (yield, bins, ring/quadrant yield, test stats, findings):

import { renderSummaryReportHtml, openHtmlReport } from '@wafertools/wafermap/stats';

const html = renderSummaryReportHtml({
  wafer, dies,
  yieldSummary:  summary.stats,
  dataCoverage:  summary.stats.dataCoverage,
  hbinDefs:      result.hbinDefs,
  sbinDefs:      result.sbinDefs,
  testDefs:      result.testDefs,
  statsSummary:  summary,
  passBins:      [1],
});
openHtmlReport(html);

Lot summary report — the lot-level equivalent, covering per-wafer yield table, bin breakdown, ring/quadrant yield, lot-level test stats, and lot findings. Grouping, per-group analysis, and rendering all happen internally — pass the raw items list, never a pre-computed lotSummary; a mixed multi-lot/multi-product/multi-temperature load is automatically split into separate labelled sections rather than pooled:

import { renderLotSummaryReportHtml, openHtmlReport } from '@wafertools/wafermap/stats';

const html = renderLotSummaryReportHtml({
  items: waferMapResults.map((r, i) => ({
    label: `W${i + 1}`,
    wafer: r.wafer,
    dies:  r.dies,
  })),
  hbinDefs:  waferMapResults[0].hbinDefs,
  sbinDefs:  waferMapResults[0].sbinDefs,
  testDefs:  waferMapResults[0].testDefs,
  passBins:  [1],
});
openHtmlReport(html);

Findings-only report — a lighter report with just the severity-coded findings table, works for both wafer and lot summaries:

import { renderFindingsReportHtml, openHtmlReport } from '@wafertools/wafermap/stats';

openHtmlReport(renderFindingsReportHtml(lotSummary));

The summary panel's "Summary report" button in renderWaferMap and renderWaferGallery calls the appropriate function automatically — you only need to call these directly when building a custom export flow.

Embedded hosts (Tauri, Electron, WebView2). In hosts where window.open is blocked, register a custom opener once at startup:

import { setReportOpener } from '@wafertools/wafermap/stats';

setReportOpener(html => {
  // route to a host-managed window, IPC call, etc.
  myApp.showReport(html);
});

All openHtmlReport calls — including the summary panel buttons — then route through your opener automatically.

14. The Insights tab¶

renderWaferMap and renderWaferGallery both support an opt-in Insights tab — a chart suite covering process capability, value distributions, and test correlation, computed from the same dies already on screen. Enable it with one option; there's no per-chart wiring and no host-computed grouping to set up.

renderWaferMap(container, result, { insights: { enabled: true } });

renderWaferGallery(container, items, { insights: { enabled: true } });

Either way, an Insights button appears in the toolbar. Clicking it swaps the map (or gallery grid) for the chart suite; clicking it again — the toolbar stays visible and usable throughout — returns to the map. Panels read parametric test values, so pass testDefs to buildWaferMap if you want capability, box plots, histograms, correlation, and scatter to have data; yield and bin pareto only need die.hbin/die.sbin.

The toolbar itself adapts: mode, palette, overlay, orientation, Expand, and Findings controls (and, in a gallery, columns/download) are hidden while the Insights tab is open — none of them apply to the chart suite, and Findings specifically toggles the map/gallery findings panel, which sits behind (or inside the now-hidden grid body of) the Insights view with no visible effect. Only Insights and User guide stay visible. Expand has no single view left to enlarge once Insights owns the screen — each chart panel inside Insights has its own expand button instead, for enlarging just that chart.

The tab lays out three sections: Yield & bins (a yield bar labelled with the actual pass bins in use, plus a hard/soft bin pareto), Distributions (process capability, a test-value box plot, and a value histogram), and Correlation (a Pearson-r matrix and a die-level X/Y scatter). Clicking a capability box drives the box plot and histogram's selected test in place; clicking a correlation-matrix cell drives the scatter panel's X/Y in place — the same live cross-linking the toolbar's own mode/colour controls give you elsewhere.

Grouping (gallery only)¶

With more than one wafer, a Group by control appears above the panels whenever wafer metadata actually varies on a groupable field (lot, product, testProgram, temperature, split, or a custom key) — nothing to configure, it's derived from wafer.metadata the same way renderWaferGallery already reads it elsewhere:

renderWaferGallery(container, items, {
  insights: { enabled: true },
  lotStatsSummary: analyzeWaferLot(items),
});

Passing lotStatsSummary (§13) also makes the yield panel reuse each wafer's already-computed yield instead of recomputing it — so the Insights tab's numbers always agree with the gallery's own Summary panel and any exported report. Each panel consumes an active grouping in whatever way suits that chart type: yield/bin-pareto/box-plot pool one row per group with click-to-drill; histogram overlays one series per group; capability and correlation restrict to one group at a time via their own "Group:" dropdown (pooling either would be statistically misleading); scatter never restricts, colouring every group's points instead. Full behavior for each panel is in the API reference.

For a single wafer, or a gallery where nothing varies, there's simply no "Group by" control to show — every panel already displays that population directly.

Narrowing to one wafer¶

Histogram, correlation, and scatter each draw one shared chart rather than one per wafer, so when ungrouped they pool every wafer by default. A "Wafer: All wafers ▾" picker on each of those three panels lets you narrow to a single wafer instead — useful when correlation or scatter's "Mixed <field>" warning appears (comparing wafers that differ on a groupable field can be misleading, the same Simpson's-paradox concern grouping addresses at the lot level).

Opening a wafer from a chart¶

Clicking a leaf row in the yield bar or the box plot opens that wafer in a modal. A box-plot click is context-aware: it opens the wafer already in test-value mode on the test you were looking at, not the toolbar's default plot mode — so drilling from "Idsat" in the box plot lands you on the Idsat colour map, not a hard-bin view you'd have to switch away from.

→ Demo: Your first wafer map and Demo: Building a lot gallery both have the Insights tab enabled — click the toolbar's Insights button in either to try it.

15. Reticle overlays¶

A reticle (stepper field) is a rectangular group of dies that the lithography tool exposes in a single step. The reticle overlay draws the field boundaries on top of the wafer map and enables reticle-position analysis in the stats engine.

Adding a reticle overlay¶

const result = buildWaferMap({
  results,
  dieConfig:     { width: 10, height: 10 },
  reticleConfig: {
    width:  4,    // 4 dies wide per stepper field
    height: 2,    // 2 dies tall per stepper field
    // anchorDie: { x: 1, y: 0 }  // optional: pin a specific die (die.x/die.y) to a
                                    // field's min-x/min-y corner (bottom-left, since +Y is up)
  },
});

renderWaferMap(container, result);
// showReticle defaults to true when result.reticles is non-empty

The toolbar shows a Reticle toggle button whenever reticles is non-empty.

Once a reticleConfig is set, every die's hover tooltip also gains a Reticle (column, row) line directly below Die (x, y), showing that die's field-local position (0-indexed, relative to anchorDie) — independent of whether the reticle overlay is currently toggled on. This is on by default with no extra configuration; custom toCanvas pipelines calling buildHoverText directly can pass reticleConfig as its final argument to get the same line.

Reticle analysis in the stats engine¶

When a reticleConfig was used, analyzeWaferMap automatically includes reticle-position comparisons (die's position within its stepper field vs. rest of reticle). This surfaces systematic problems from mask defects, focus variation, or lens aberrations:

const result  = buildWaferMap({ results, dieConfig, reticleConfig });
const summary = analyzeWaferMap(result, { enableReticlePositionAnalysis: true });
// result.reticleConfig is passed through automatically

Reticle overlay in a gallery¶

Spread the result directly — r.reticles is already part of WaferMapResult. The gallery enables the Reticle toggle button automatically when any item has reticles: