PivoGraph project file format (.pivograph), schema version 2

The JSON Schema is generated from the same validator the application uses, so it is authoritative for field names, enumerations and limits. This page explains the semantics that a schema cannot express.

What changed since version 1

Version 2 collects every change to the document structure and to rendering defaults made for PivoGraph 1.6. A version 1 document is still a valid starting point: everything below either adds optional fields or is converted on open.

• Rich text. Every text field that is drawn on the graph — graph / X / Y titles, free text, the label of a significance bracket, text bound to a drawing shape, and custom legend labels — is now a rich text value: either a plain string or { "runs": [...] } with per-run bold / italic / superscript / subscript. Plain strings are taken literally; the ^{…} / _{…} markup of version 1 is no longer interpreted. See Rich text values.
• Title rotation (axesOverrides.titlesAndFonts.<title>.rotation) is a number in degrees (clockwise positive) instead of the names horizontal / verticalUp / verticalDown.
• Line spacing. Multi-line free text, titles and shape-bound text carry an optional lineSpacing (shapes: textLineSpacing) in points.
• Category label weight. axesOverrides.xCategorical.labelBold switches the bold category labels of column-type graphs off.
• Text distance of annotation lines. The default textGap of shape-bound text is 3 points (version 1 drew it at 1.5).
• Exploded pie / donut slices. New optional element partsExplode (off by default) in elementActivation, keyed per slice by the slice's row index; the offset lives in the bar style as explodeOffsetPt.
• Fitted-curve draw order. The curve style carries drawOrder: underneath (default; the curve is drawn behind the data points) or onTop.
• Stacked-bar error bars. grouped-stacked-bars accepts the optional errorBar element (on by default; each segment's error bar is centred on the segment's outer edge, extends to both sides and is drawn on top of all segments).
• Significance bracket formatting. bracket annotations accept the same line and text formatting as text-bearing shapes: dashStyle, lineColor, fontFamily, base bold / italic, textRotation, textLineSpacing and textGap (default 3, the same as annotation lines) join the existing lineWidth, fontSize and textColor. Brackets did not store a text distance in version 1 and drew it at 1.5 points; old brackets are not migrated to keep that value, so their label sits 1.5 points higher than before.
• Summary symbols on scatter plots. New optional element summarySymbol (off by default) on the scatter variants of Column, Grouped and Nested graphs (column-scatter-only, grouped-interleaved-scatter, grouped-separated-scatter, grouped-superimposed-scatter, nested-scatter): a second symbol drawn at each group's mean / median on top of the individual points and error bars, styled by the summarySymbol entry of styleOverrides (same fields as symbol; default a white-filled bordered circle of size 6 whose border follows the data set colour). On the same variants the summary line (summaryLine) became an optional element that is on by default, so it can be switched off.
• More heat map colour scales. plot.options.heatMap.colormap also accepts viridis, magma, cividis (perceptually uniform sequential scales) and purpleOrange (diverging purple – white – orange). Unlike sequential and diverging, these scales do not follow the theme.
• Heat map colour bar length. The default colorScaleBar.lengthRatio is 1 (the full plot height); version 1 drew it at 0.6, and heat maps from version 1 files keep that value.
• Edge spacing of bar layouts. graphSettingsOverride.firstGapRatio / lastGapRatio are "auto" (default) or a number ≥ 0: the clear distance from the plot edge to the outer edge of the first / last bar, as a fraction of the bar slot (the row slot on grouped graphs), so 0 puts the bar flush with the edge while the spacing between bars is kept. "auto" leaves half the space between bars, as before. In version 1 the numbers were extra padding added on top of that half space; version 1 values are converted on open (0 becomes "auto", larger values keep their visible distance).
• Before-after in grouped rows. grouped-rm-across-row defaults to plot.options.seriesAlign: "staggered", so the data sets of a row sit side by side and each subject's values (same sub-column) are joined across the row. Its connecting lines follow the graph-level line style (colour, thickness, dash); the connecting lines of grouped-rm-in-subcol now also follow the line dash style. In version 1 the across-row default was "aligned" and its lines were always solid dark grey. Version 1 across-row graphs get seriesAlign: "aligned" when it is not set, and a global line colour of #3f3f46 unless a concrete line colour is already set globally or for the first plotted data set. Line colours and dash styles that were set explicitly in version 1, and that these connecting lines ignored, apply from version 2.
• Brackets on grouped graphs. A bracket anchor may carry rowIndex to snap to one data set in one row of a grouped graph (see Annotations and titles).
• Per-row t-tests. New analysis method rowTTests for grouped tables (see Analyses).

Migration of version 1 files. The migration runs in memory when a version 1 file is opened and makes the explicit choices that keep the old appearance: markup in free text, titles, shape text and legend labels becomes runs (an unclosed ^{ or _{ stays literal); bracket labels and data set names are never parsed; rotation names become degrees; texts that already contain a line break get lineSpacing: 0; shape-bound text without an explicit textGap gets textGap: 1.5; tables that carry a linearRegression / nonlinearRegression analysis get styleOverrides.global.curve.drawOrder: "onTop"; heat maps get styleOverrides.global.colorScaleBar.lengthRatio: 0.6; numeric firstGapRatio / lastGapRatio are converted to the new clear-distance meaning; grouped-rm-across-row graphs get seriesAlign: "aligned" and the former dark-grey line colour. The only intended visible difference is the label of significance brackets without an explicit textGap, which moves up by 1.5 points. The original file is never rewritten; saving writes a version 2 document.

1. File basics

• Plain UTF-8 JSON, no byte-order mark (a leading BOM is tolerated when reading). Extension .pivograph; MIME type application/json. Where a tool needs the JSON language recognised from the file name, .pivograph.json is also accepted when opening.
• The whole document is one JSON object. Unknown keys are rejected at every level with the JSON path of the offending key. Tool-specific data belongs in usermeta (document level or per table).
• Everything in the file is data. There is no executable content, no external references are fetched when a file is opened, and the application never downloads the $schema URL.
• Write complete, read tolerant. PivoGraph writes resolved document state explicitly so that saved settings do not silently inherit future defaults. Hand-written or generated documents may omit any optional field — and may give any nested object partially; the application fills its current defaults. Optional fields are expressed by omitting the key; null is only valid where the field's type includes it (missing cells, unmapped variable roles, automatic geometry).
• Opening reports two kinds of problems: errors (the file is not opened; the current project is untouched) and warnings (the file opens, but the listed parts were ignored or replaced by defaults, for example a style override keyed to a data set that does not exist). Both carry JSON paths.

2. Envelope

{
  "$schema": "https://pivograph.com/schemas/project/v2.json",
  "format": "pivograph-project",
  "schemaVersion": 2,
  "generator": { "name": "PivoGraph", "version": "1.6.0", "url": "https://pivograph.com" },
  "createdAt": "2026-09-06T10:00:00.000Z",
  "modifiedAt": "2026-09-06T12:00:00.000Z",
  "meta": { "title": "Dose response" },
  "usermeta": {},
  "view": { "activeTableId": "dose", "workspaceView": "graph" },
  "tables": []
}

• format (required): always "pivograph-project". Together with schemaVersion this is how a reader recognises the file; $schema is informational.
• schemaVersion (required): integer. See "Versioning".
• tables (required): array of tables in sidebar order (maximum 200). A minimal valid document is exactly format + schemaVersion + tables.
• generator (optional): the program that wrote the file (name, version, optional url). Purely informational; PivoGraph always writes it.
• createdAt / modifiedAt (optional): ISO 8601 timestamps with timezone. PivoGraph keeps createdAt from the first save and rewrites modifiedAt.
• meta (optional): title (required inside meta, may be empty), optional description, authors[], license, source, keywords[]. license and source are meant for example / template projects.
• usermeta (optional): a JSON object for tool-specific data. Its JSON value is preserved across save and reopen, never interpreted, and limited to 64 KB when serialised; whitespace and object formatting are not preserved.
• view (optional): which table is active (activeTableId, must be an explicit table id) and whether the editor opens in "table" or "graph" view. This is the only presentation state in the file.

3. Tables

Each table is one data table of one of the eight families: xy, column, grouped, nested, contingency, survival, partsOfWhole, multipleVariables.

{
  "id": "dose",
  "name": "Dose response",
  "format": "xy",
  "replicates": 3,
  "x": [-9, -8, -7],
  "rowLabels": ["low", "mid", "high"],
  "dataSets": [
    { "name": "Control", "values": [[1.1, 1.2, null], [2.0, 2.1, 1.9], [5.0, 4.8, 5.1]] },
    { "name": "Treated", "values": [[0.9, 1.0, 1.1], [1.5, 1.6, 1.4], [2.9, 3.1, 3.0]] }
  ],
  "graph": { "variantId": "xy-points-error" },
  "analyses": [],
  "annotations": [],
  "titles": {},
  "usermeta": {}
}

• format (required): the family.
• dataSets (required unless derivedFrom is present; at least one): one entry per data set, corresponding to the table's data columns. values[row][replicate] holds finite numbers, null for missing, or text. Rows may be shorter than replicates (missing cells are filled with null). Data set names must be unique within a table.
  • Text is accepted only in multipleVariables tables (text categories and labels). In every other family a text cell is an error, except that numeric-looking strings such as "1.5" are read as numbers.
  • name is the stable key that styles, analyses and variableTypes refer to. title (optional) is the label shown on the graph and in panels; it may repeat across data sets. When omitted the label equals name; null means the data set has no label (the legend shows a placeholder and category axes stay blank). Data set names and titles are plain strings and are always drawn literally.
  • subColumnTitles (optional, nested tables only): one label per sub-column of this data set (null = none), aligned with replicates; these appear on the category axis.
• replicateTitles (optional, tables whose sub-columns are shared, e.g. xy / grouped): one label per sub-column (null = none), aligned with replicates. Spreadsheet headers only; not drawn on the graph.
• id (optional): any non-empty string (≤ 128 characters), unique among tables; generated when omitted. Tables referenced by derivedFrom or view.activeTableId need an explicit id. Human-readable slugs are fine.
• name (optional): defaults to Table N.
• replicates (optional): number of sub-columns per data set. Fixed at 1 for column, contingency, survival, partsOfWhole and multipleVariables; ≥ 2 for nested; free for xy and grouped. When omitted it is inferred from the widest row (never below the family minimum).
• x: only for xy and survival — the shared X column, one entry per row, aligned with values. In survival tables X is time and the cells are event codes (1 = event, 0 = censored).
• rowLabels: optional row titles (categories for grouped / contingency / partsOfWhole, sample names for heat maps).
• variableTypes: multipleVariables only — explicit overrides of the inferred variable type (continuous, categorical, label) keyed by variable (data set) name.
• columnWidths: optional spreadsheet column widths; presentation only.
• usermeta: optional tool-specific data for this table; same rules as the document-level slot.
• derivedFrom: marks a results table produced by an analysis on another table: { "sourceTableId", "analysisId" }. Such tables carry no dataSets, x, rowLabels or variableTypes; their content is recomputed when the file opens. The referenced analysis must exist on the source table (with an explicit id) and must be one that produces a results table (frequencyDistribution, correlationMatrix).
• Row count is the longest of x, rowLabels and any values; trailing empty rows are not stored.

4. Graph

graph is the graph document of the table (one graph per table). Only variantId is required; every other field, and every nested object inside them, may be given partially.

• variantId: a graph variant from the PivoGraph registry, for example bar, column-box-whiskers, xy-points-line-error, grouped-heat-map, survival-staircase-ticks, parts-donut, mv-volcano. The full list is the GraphVariantId definition in the JSON Schema. The variant must belong to the table's family and be available for the table's replicate count (for example xy-points-error needs replicates > 1).
• plot: statistical / topology options of the family ({ "family": "...", "options": {...} }); family must equal the table format. Options are merged over the defaults of the variant; a mode that the variant does not offer is replaced by the variant default with a warning. For multipleVariables tables plot is required because it carries the variable mapping: plot.options.kind must match the variant (bubble → mv-bubble, scatter → mv-scatter, volcano → mv-volcano, forest → mv-forest) and plot.options.mapping gives data set indexes per role (x required; y, size, color, shape, label, lower, upper as the plot kind requires; omitted roles are unmapped).
• activePresetId: built-in theme preset (modern, classic, floral, starry). applyPresetNonColor: whether the preset's non-colour constants are applied.
• styleOverrides: user overrides on top of the theme, in three layers — global, perDataSet (keyed by data set name, or a semantic key such as volcano:up) and perPoint (data set name → point index). Each layer is a partial patch per element kind (bar, symbol, errorBar, line, …). Colours are either "theme" (follow the preset) or { "hex": "#rrggbb", "alpha": 0.8 }; hex colours have 3 or 6 digits and transparency always goes in alpha. Two fields worth knowing: bar.explodeOffsetPt (points, default 2) is the distance an exploded pie / donut slice moves away from the centre (pie slices reuse the bar style; perPoint is keyed by the slice's row index), and curve.drawOrder (underneath default / onTop) places a fitted curve and its confidence band behind or in front of the data points. summarySymbol carries the same fields as symbol and styles the optional mean / median symbol of scatter variants independently of the individual points.
• graphSettingsOverride: partial graph settings (bar width, gaps, baseline, line of identity, …).
• axesOverrides: six partial buckets (frameAndOrigin, xCategorical, xContinuous, leftY, rightY, titlesAndFonts); "auto" means automatic where a number is otherwise expected. Nested objects (grid lines, tick appearance, number format, title font) may be partial. Title text is not part of the axes — see titles. Additional ticks / reference lines (additionalTicks) may carry lineColor and lineThickness; when omitted the line follows the axis colour and the major grid width.
  • titlesAndFonts.graphTitle / xAxisTitle / yAxisTitle: font (family, size, bold, italic — the base style of the title, see Rich text values) and rotation in degrees, clockwise positive, normally a multiple of 45 (defaults: 0 for the graph and X titles, −90 for the Y title).
  • xCategorical.labelBold (boolean, default true): whether the category labels of column-type graphs are bold.
• plotGeometry: plot-area size in points (null or omitted = automatic).
• dataSetVisibility: data set index (as a string key) → false to hide; missing = visible.
• elementActivation: optional-element switches in three scopes (global, perDataSet by index, graph). Which elements a variant offers is fixed by the registry (for example errorBar on grouped-stacked-bars — on by default — summarySymbol and summaryLine on the scatter variants — off / on by default — and partsExplode on parts-pie / parts-donut — off by default). For pie and donut graphs perDataSet is keyed by the slice's row index, so a single slice can be exploded. Switches for elements the variant does not offer are accepted and have no effect.
• legend: legend configuration including itemOverrides keyed by data set index or semantic id. bold / italic are the base style of the whole legend; an item's label is a rich text value (see below) that replaces the data set label.
• partsOfWholeBorders: outer / inner border of pie, donut and slice graphs.

Keys that refer to data sets by name and keys that refer to them by index coexist in version 2 (they mirror the application's model). Keys that match no data set are ignored with a warning. A future schema version may unify them; documents will be migrated automatically.

A graph that uses several of the version 2 fields — a Column scatter plot with a white mean symbol drawn over semi-transparent points, the summary line switched off, the first group flush with the left edge of the plot, regular-weight category labels and a Y title rotated to read upwards:

{
  "variantId": "column-scatter-only",
  "plot": { "family": "column", "options": { "mode": "meanWithSd" } },
  "styleOverrides": {
    "global": {
      "symbol": { "color": { "hex": "#1f77b4", "alpha": 0.35 } },
      "summarySymbol": { "size": 7, "borderColor": { "hex": "#000000" } },
      "errorBar": { "color": { "hex": "#000000" } }
    }
  },
  "elementActivation": { "global": { "summarySymbol": true, "summaryLine": false } },
  "graphSettingsOverride": { "firstGapRatio": 0, "lastGapRatio": "auto" },
  "axesOverrides": {
    "xCategorical": { "labelBold": false },
    "titlesAndFonts": { "yAxisTitle": { "rotation": -90 } }
  }
}

5. Analyses

analyses is a list of analysis instances attached to the table: { "id", "method", "params" }. id is optional (generated when omitted; required when a results table refers to it) and params may be partial (method defaults fill the rest). Results are not stored; they are recomputed from the data and the parameters.

• ttest (column, xy): { "groupA": "name" | null, "groupB": "name" | null, "design": "unpaired" | "paired", "variance": "welch" | "equal" }. Group names refer to data set names; null uses the first two populated data sets.
• rowTTests (grouped, needs at least two sub-columns): the same parameters as ttest; groupA / groupB name the two data sets that are compared in every row. Each row is tested on its own, and P values are not adjusted for multiple comparisons. With "design": "paired" the values in the same sub-column of a row belong to one subject; sub-columns without a value on both sides are skipped. Significance brackets for the rows can be added to the graph (see the rowIndex anchor in Annotations and titles). Example: { "method": "rowTTests", "params": { "groupA": "Before", "groupB": "After", "design": "paired" } }.
• linearRegression (xy): { "confidenceLevel": 90 | 95 | 99 }.
• nonlinearRegression (xy, four-parameter logistic): { "model": "logX" | "linearX" }.
• frequencyDistribution (column): { "binWidth": number | null, "binStart": number | null, "output": "count" | "fraction" | "percent", "cumulative": boolean }. Produces a results table (grouped).
• correlationMatrix (multipleVariables): { "method": "pearson" | "spearman" }. Produces a results table (grouped) rendered as a heat map.
• survivalComparison (survival): { "showPValue": boolean, "showHazardRatio": boolean, "showMedians": boolean }. Log-rank (Mantel-Cox) and Gehan-Breslow-Wilcoxon tests across all curves, hazard ratio for two curves and median survival per data set; the switches only choose the lines of the text that can be placed on the graph.

A method must be available for the table's family. Explicit analysis ids must be unique within their table.

6. Rich text values

Text that is drawn on the graph is a rich text value — one of two forms:

"Cell number"

{
  "runs": [
    { "text": "Cell number (×10" },
    { "text": "6", "baseline": "super" },
    { "text": ")" },
    { "text": "\nper well", "italic": true }
  ]
}

• A plain string is drawn literally — there is no markup. \n starts a new line.
• The runs form concatenates its runs in order. Each run has text (non-empty; may contain \n) and optional bold, italic (booleans) and baseline ("super" or "sub"). Omitting bold / italic means inherit the base style of the object (the title font, the free text's or shape's bold / italic, or the legend's bold / italic); giving false explicitly overrides an inherited bold / italic. Omitting baseline means normal position; super- and subscripts are drawn at reduced size and shifted. Formatting cannot nest beyond these three properties.
• Limits: at most 500 runs per value; the concatenated text obeys the general string limit. Adjacent runs with identical formatting and empty runs are accepted but PivoGraph normalises them when saving, and writes the plain-string form whenever no run carries formatting.

Rich text values appear in: titles.graph|x|y.text, annotations[].text (all three annotation types), and graph.legend.itemOverrides.<key>.label. Data set names and titles, row labels and axis numbers are plain strings and are never parsed.

7. Annotations and titles

annotations holds drawing objects placed on the graph, discriminated by type (id optional, generated when omitted):

• bracket: significance bracket. left / right anchors are { "kind": "group", "groupIndex": n } (snapped to the n-th plotted data set), { "kind": "group", "groupIndex": n, "rowIndex": r } on grouped graphs (the n-th plotted data set in row r; available when the data sets of a row sit side by side — interleaved or separated layouts, or staggered series), or { "kind": "free", "x": pt }; y is the bar position, leftFootLen / rightFootLen the foot lengths, text the label ("*", "ns", … — a rich text value). Line formatting: lineWidth, dashStyle, lineColor. Text formatting: fontSize, fontFamily, textColor, base bold / italic, textRotation in degrees (multiples of 45, about the label centre), textLineSpacing in points and textGap — distance between label and bar in points, default 3. Labels that consist only of asterisks are drawn enlarged and aligned to the text baseline.
• text: free text at x, y (points): text (rich text value), fontSize, fontFamily, color, base bold / italic, rotation in degrees (multiples of 45, about the centre of the text block), and lineSpacing — extra space in points between lines when the text has more than one line (default 2).
• shape: lines, arrows, rectangles, ellipses, brackets, … (shape enum), with two or three control points and optional bound text (text rich text value, textRotation in degrees, textLineSpacing in points, textGap — distance between text and line in points, default 3 — and base bold / italic). A two-point line with text is always drawn horizontal or vertical (the end point is projected onto the nearer axis); a two-point line without text keeps the exact angle its end points describe. Closed shapes (circle, ellipse, square, rectangle, rounded rectangle) may carry fillColor; omitted means no fill.

A significance bracket between the two data sets of the first row of a grouped graph, with a dashed line and an italic two-line label:

{
  "type": "bracket",
  "left": { "kind": "group", "groupIndex": 0, "rowIndex": 0 },
  "right": { "kind": "group", "groupIndex": 1, "rowIndex": 0 },
  "y": 24,
  "text": { "runs": [{ "text": "P = 0.012\n", "italic": true }, { "text": "n = 8" }] },
  "dashStyle": "dashed",
  "textGap": 3,
  "textLineSpacing": 1
}

titles overrides the graph, X and Y titles (graph, x, y): text (rich text value), drag offset (dx, dy), fontSize, fontFamily, color and lineSpacing. This is the only place where title text lives; the title's base bold / italic and its rotation live in axesOverrides.titlesAndFonts.

8. Versioning and compatibility

• schemaVersion is an integer. Every change to the document structure or to rendering-relevant defaults increases it by one and ships with a migration step. Migrations run once, at open time, before validation.
• A reader opens every version from 1 up to its own. Older files are migrated in memory; the original file is never rewritten.
• A file with a newer schemaVersion than the reader supports is refused with an explicit message (in the web application: reload the page to get the latest version). Nothing is guessed or silently dropped.
• Registry identifiers (variants, presets, methods, symbols, colormaps) are part of the format contract. Deprecated identifiers are handled by migrations, not by aliases.
• Every version has exactly one JSON Schema (/schemas/project/v<N>.json, immutable), one specification page (/developers/project-format/v<N>/, plus the Markdown copy v<N>.md) and one set of examples, listed in /schemas/project/v<N>/examples/index.json. /schemas/project/index.json lists all versions and which one is current. There is deliberately no "latest" schema URL: a file's $schema must stay stable.
• Fixtures of every published version are kept in the repository and tested on every build.

9. Limits

Files larger than 50 MB, more than 200 tables, more than 2,000,000 cells in total, more than 200,000 rows or 500 data sets per table, more than 2,000 annotations or 200 analyses per table, more than 500 runs in one rich text value, non-finite numbers, over-long strings, or record keys named __proto__, constructor or prototype are rejected. Exact values are in the JSON Schema.

10. Validation

Opening a file goes through: size limit → strict UTF-8 → JSON parse → envelope (format, schemaVersion) → version gate → forbidden-key scan → migration → strict structural validation (JSON Schema equivalent) → semantic validation → import. Semantic errors include: duplicate ids, dangling derivedFrom or view.activeTableId references, replicate counts invalid for the family, variant / plot family not matching the table, variant unavailable for the replicate count, incomplete variable mapping, analysis methods unavailable for the family, text cells outside multipleVariables, rows wider than replicates, total cell count. Semantic warnings include: style / visibility / legend keys that match no data set, and plot modes the variant does not offer.

All problems are reported together with JSON paths (for example tables[0].graph.variantId). If any error occurs, the current project in the editor is left untouched.

11. Minimal example

{
  "format": "pivograph-project",
  "schemaVersion": 2,
  "tables": [
    {
      "name": "Cell viability",
      "format": "column",
      "dataSets": [
        { "name": "Vehicle", "values": [[98], [102], [95]] },
        { "name": "Compound", "values": [[71], [68], [74]] }
      ],
      "graph": { "variantId": "scatter-bar", "plot": { "family": "column", "options": { "mode": "meanWithSd" } } }
    }
  ]
}

More examples, one per table family, are listed in https://pivograph.com/schemas/project/v2/examples/index.json (each entry gives the file URL and the table families, graph variants and analyses it uses; the Developers page links them individually); representative.pivograph is a complete document written by PivoGraph itself.

12. For AI assistants

PivoGraph's Help menu offers Copy Prompt for AI Assistants…: a prompt generated from the running version that lists every family, variant id, analysis method, the main format rules, and a minimal example. Give that prompt to an AI assistant, describe the data and intended figure, save the returned JSON as .pivograph, and open it in PivoGraph. Treat generated projects as drafts: verify the source values, analysis choices, and graph before using the result. Agents can also use this page, its Markdown copy, llms.txt, the JSON Schema, and the examples.

Changelog

• v2 (PivoGraph 1.6) — rich text values (plain string or runs with bold / italic / super- / subscript; no markup), title rotation in degrees, lineSpacing / textLineSpacing, xCategorical.labelBold, shape textGap default 3, partsExplode element + bar.explodeOffsetPt, curve.drawOrder, optional errorBar on stacked bars (on by default), line / text formatting fields on bracket annotations, summarySymbol element + style on scatter variants (with summaryLine now optional), heat map colormaps viridis / magma / cividis / purpleOrange, colour bar length default 1, edge spacing firstGapRatio / lastGapRatio as clear distance with "auto" default, grouped-rm-across-row staggered by default with connecting lines that follow the line style, rowIndex on bracket anchors, rowTTests analysis. Version 1 files are migrated automatically.
• v1 — first public version (PivoGraph 1.3). Specification v1 stays available.