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Changelog

Source: NEWS.md

myIO (development version)

New features

  • New setTransition(duration, easing, stagger) configures chart animations: duration in milliseconds, easing (one of "linear", "quad", "cubic", "sin", "exp", "circle", "back", "bounce", "elastic", mapped to the corresponding d3 easing), and stagger (per-element cascade delay in ms). All arguments are optional and additive; unset values keep each renderer’s existing defaults, so the change is fully backward compatible. setTransitionSpeed() is now a thin wrapper over setTransition(duration = ). Animation stays fully opt-out-able: duration = 0 disables it, and easing and stagger automatically no-op when the effective duration is 0, including under the viewer’s prefers-reduced-motion: reduce system setting. A Playwright e2e spec verifies animate-when-on, still-when-off, and still-under-reduced-motion.
  • New opt-in "lttb" transform for line layers downsamples a large series with Largest-Triangle-Three-Buckets, shipping at most options$threshold points (default 2000) while preserving the visual shape: addIoLayer(type = "line", transform = "lttb", options = list(threshold = 1000)). Off by default (identity); runs on the in-memory/SVG path and is independent of the DuckDB-WASM engine’s own SQL-side LTTB, so it never double-downsamples.
  • New myIOProxy() + updateMyIOData() update a rendered chart’s layer data in place from the Shiny server without re-running renderMyIO(). Layers are matched by label and swapped through the existing data-join path, so only the changed marks transition and brush/zoom/toggle state is preserved (the full re-render destroyed and recreated the chart, flickering and dropping state): myIOProxy("chart") |> updateMyIOData(series = new_df).

Performance and tooling

  • The production JavaScript bundle is now minified. The shipped inst/htmlwidgets/myIO/myIOapi.js drops from 2.32 MB to 1.20 MB raw (398,650 to 298,757 bytes gzipped, -25%) with no behavior change; the development watch build stays unminified for debugging.
  • End-to-end tests now run from a committed playwright.config.ts and a new e2e CI workflow. The suite builds and loads the minified myIOapi.js, guarding the production bundle that source-importing unit tests cannot catch.
  • Touch interaction is now verified end-to-end: a touch-emulation Playwright spec on iOS- and Android-class viewports confirms a touchstart on a bar surfaces the tooltip with the datum’s content and touchend dismisses it, guarding the mobile hover path against the production bundle.
  • The file:// deployment e2e (self-contained widget opened directly from disk) is now exercised for real: its fixture loads the IIFE bundle via a classic <script src> rather than an ES module, so the file-protocol → SVG-engine fallback is verified under file:// instead of skipped.

Improved error messages and API ergonomics

  • Argument names are now consistently camelCase across setters. setBrush(onSelect), setFacet(minWidth, labelPosition), setTheme(textColor, gridColor), and setBigData(rowkeyCol) are the canonical forms (matching colorScheme, xAxis, etc.). The previous snake_case names (on_select, min_width, label_position, text_color, grid_color, rowkey_col) keep working as deprecated aliases that emit a one-line warning; existing code is unaffected aside from the warning. When both forms are supplied the camelCase value wins.

  • setFacet(), setLayerOpacity(), and setTheme(mode = ) now report invalid arguments with consistent, actionable messages (e.g. setFacet(): \scales` must be “fixed”, “free_x”, “free_y”, “free”, not “x”.) instead of barestopifnot()failures.setColorScheme()` errors are likewise function-prefixed. No change to which inputs are accepted.

  • setTheme() now warns when passed an unknown argument that lacks the required -- prefix (e.g. a misspelled text_colour) and suggests the intended argument, instead of silently dropping it. Valid ---prefixed CSS overrides are unaffected.

  • setTheme() documents the named preset values ("midnight", "ocean", "forest", "sunset", "monochrome", "neon", "corporate", "academic", "nature", "minimal", "retro", "warm", plus "light"/"dark"); the preset argument was already functional.

  • setLinked() and linkCharts() now cross-reference each other in their documentation to clarify when to use the Crosstalk path versus the group-identifier path. ## Documentation

  • New “Theme Gallery” article renders the same chart under all named presets (midnight, ocean, forest, sunset, monochrome, neon, corporate, academic, nature, minimal, retro, warm, plus light/dark) as live, side-by-side previews, and shows how to layer custom CSS overrides on top of a preset. ## Performance and reliability

  • Inline Arrow IPC payloads now decode via the native Uint8Array.fromBase64 when the browser provides it (falling back to the previous atob loop), avoiding a per-character JavaScript callback over large payloads in the in-memory and DuckDB-WASM engines.

  • Added a regression test confirming charts that already render an inline legend are not given a duplicated legend on image/SVG export (GH #64).

  • Layer-data serialization (addIoLayer()) is faster for large data: the row-rectangling step now extracts columns once and indexes per row instead of subsetting the data frame on every row, roughly 5x faster at 100k rows. The emitted JSON is byte-identical to before (pinned by tests across numeric, integer, character, logical, factor, Date, and POSIXct columns), so every chart type renders exactly as it did.

myIO 1.2.0

CRAN release: 2026-06-11

LLM tool-calling schema

  • New machine-readable chart specification schema (inst/myio-schema.json) describing all chart types, required mappings, valid transforms, and function signatures, generated from the package’s own contracts.
  • Six exported R tools let large language model agents author and verify charts against that schema: myio_list_chart_types(), myio_chart_schema(), myio_validate_spec(), myio_list_functions(), myio_function_signature(), and myio_validate_call(). A Model Context Protocol server in the package’s source repository exposes the same six tools to MCP-compatible clients.
  • New vignette llm-tool-calling demonstrates a generate-validate-repair loop.

Uncertainty visualizations

  • New quantile_dots chart type and quantile_dots transform render a Wilkinson dot plot of predictive quantiles for communicating uncertainty.
  • New fan composite renders a fan chart of nested prediction intervals around a central estimate.
  • myIO(title = ...) and setTitle() add a backward-compatible chart title surface rendered inside the SVG. Existing charts that omit a title are unchanged.
  • Axis titles from setAxisFormat(xLabel = ..., yLabel = ...) now render in the chart SVG, and multi-series charts get a compact visible legend while preserving the existing action-sheet legend.
  • The gallery now carries chart titles across examples, repairs horizontal bars, mean-CI, heatmap margins, gauge thresholds, treemap labels, date-based finance examples, and shows themes across a small grid of representative charts.

Crosstalk: expanded chart-type coverage

  • setLinked() now links waffle, beeswarm, lollipop, and dumbbell layers in addition to the previously supported point, bar, groupedBar, histogram, and hexbin. Selection dims non-matching elements; filter hides them. Aggregate chart types (boxplot, violin, qq, regression, density, ridgeline, survfit, comparison) remain outside crosstalk in v1.2.
  • New vignette crosstalk-linking demonstrates linking myIO with DT::datatable() and reactable::reactable(), with code listings for plotly and leaflet.

bslib and Quarto Dashboards integration

  • myIO() widgets now declare a sizing policy with browser.fill = TRUE and are tagged as html-fill-item via htmltools::bindFillRole(), so they fill container height inside bslib::card(), Quarto Dashboard {.fill} cards, and flexdashboard layouts. Rendering in plain RMarkdown and Shiny at the default 400px height is unchanged.
  • Widget resize is now guarded against zero-dimension containers that can appear briefly during fill-layout transitions.

Calendar heatmap

  • New calendarHeatmap chart type — GitHub-contributions-style grid of daily cells over a single calendar year. Usage: addIoLayer(type = "calendarHeatmap", data, mapping = list(date = "day", value = "x")). Supports Sunday or Monday week starts via options$weekStart, continuous color legend, and linked-cursor sync across two linked calendars. Multi-year data is rejected in v1.2; multi-year layouts are planned for v1.3. New CSS variables: --chart-calendar-cell-gap, --chart-calendar-cell-stroke, --chart-calendar-empty-fill.
  • 12 named theme presets: setTheme(preset = "midnight"). Available presets: midnight, ocean, forest, sunset, monochrome, neon, corporate, academic, nature, minimal, retro, warm. Plus light/dark via mode parameter.

Linked brushing

  • linkCharts(chart1, chart2, on = "column") enables cross-chart selection. Brush in one chart highlights matching rows in linked charts. Works in Shiny and static HTML. Aggregation-to-source-row key resolution for summary views.

Linked cursor

  • linkCharts() and setLinked() gain a cursor = TRUE argument that draws a synchronized vertical crosshair on every linked chart when the user hovers any chart in the group. Supports point, bar, line, area, groupedBar, hexbin, and histogram layers (donut and treemap are excluded — no x-axis to sync on). Off by default; enable per-link or retrofit with setLinkedCursor() on a pre-linked widget. New --chart-cursor-rule-color/-width/-dasharray CSS variables theme the crosshair.

Group-by auto-series

  • Pass a dplyr::group_by() tibble to addIoLayer() and it auto-creates one layer per group with colors from the Okabe-Ito palette. Soft dplyr dependency.

Survival curves (Kaplan-Meier)

  • addIoLayer(type = "survfit", mapping = list(time = "time", status = "status")) computes Kaplan-Meier estimator with Greenwood CI using base R only (no survival package dependency). Composite expands to step-curve line, CI band, and censored-observation markers. Group stratification supported.

Distribution fitting overlay

  • addIoLayer(type = "histogram_fit", mapping = list(value = "x"), options = list(family = "normal")) fits normal, lognormal, or exponential distributions via MLE. Composite renders histogram + fitted density curve + optional parameter annotation.

Layer opacity control

  • setLayerOpacity(label, opacity) sets per-layer opacity (0-1). Critical for CI bands overlaying scatter data.

SVG accessibility

  • ARIA roles (graphics-document, graphics-object, graphics-symbol) applied to SVG chart structure for screen reader navigation.
  • Keyboard navigation: arrow keys traverse layers and data points, with live region announcements (150ms debounce).
  • Hidden data table fallback for screen reader access to raw data (capped at 500 rows).
  • Focus ring styling and screen-reader-only utility class.

New chart types

  • lollipop — vertical stem with circle head, supports mean and summary transforms. Compatible with categorical x-axis charts.
  • dumbbell — connected dots showing a range between low_y and high_y.
  • waffle — 10x10 grid of colored squares representing proportions. Standalone.
  • beeswarm — dodge-positioned points to avoid overlap. Inline dodge algorithm.
  • bump — smooth S-curves showing rank/value changes over time with grouped lines.
  • radar — spider/radar chart with radial axes and polygon data fill.
  • funnel — narrowing horizontal bars for conversion pipeline data.
  • parallel — parallel coordinates for multivariate exploration. All new types support themed colors and standard tooltip formatting.

Small multiples / faceting

  • setFacet(var, ncol, scales) splits charts into a CSS grid of panels, one per unique value of the faceting variable. Supports fixed and free scale modes, auto-layout with configurable minimum panel width, and responsive breakpoints.

Export enhancements

  • setExportOptions() controls which export buttons appear in the toolbar (PNG, SVG, clipboard, CSV). New SVG download button and clipboard copy (SVG + PNG) via the Clipboard API.
  • CSS custom properties resolved in exported SVGs for correct dark-mode colors.

Dark mode / theme system

  • setTheme(mode = "dark") applies a WCAG AA-verified dark palette across all chart elements. Also supports "light" and "auto" (detects OS preference and Quarto/Bootstrap data-bs-theme).
  • Backward compatible: existing setTheme(bg = "#fff") calls still work.
  • New overrides parameter for fine-grained CSS custom property control.
  • High-contrast and reduced-motion CSS media query support.

Sparkline mode

  • myIO(sparkline = TRUE) renders a compact, axes-free chart suitable for embedding in table cells (reactable, DT, gt). Strips legend, axes, reference lines, and all interactions. Default height 20px. Supports line, bar, and area layer types.

Bug fixes

  • myio_validate_spec() and the chart specification schema no longer reject valid specs for chart types with a single required mapping (for example histogram, gauge, and qq). The schema now always represents list-typed fields as arrays.

myIO 1.1.0

I/O interaction system

myIO now supports bidirectional data flow — user interactions return structured data, not just visual feedback.

  • setBrush(): rectangle brush selection on point, bar, histogram, hexbin, and grouped bar charts. Selected points available as Shiny reactive input or scoped CSV export in static HTML.
  • setAnnotation(): click any data point to attach a label. Annotations stored as structured data (source key, coordinates, label, category color, timestamp) and exportable as CSV. Supports preset label dropdowns and color category pickers.
  • setLinked(): Crosstalk SharedData integration for cross-widget linked brushing. Selection dims non-matching points; optional filter mode hides them. Supports source, target, or bidirectional modes.
  • setSlider(): parameter sliders below the chart that trigger Shiny re-rendering with configurable debounce. Renders disabled with tooltip in static HTML.

Bug fixes

  • dragPoints() now correctly emits the dragEnd event to Shiny (input$myIO-{id}-dragEnd), which was previously registered but never fired.

myIO 1.0.0

Statistical transforms

  • New composable transform pipeline: type + transform = layer. Transforms compute statistics in R; renderers display them in D3.js.
  • Transforms: lm, loess, polynomial, ci, smooth, mean, mean_ci, residuals, summary, pairwise_test, qq.
  • Composite chart expansion: complex charts decompose into primitive layers.

Chart types (20)

  • Basic: line, point, bar, area, groupedBar.
  • Statistical: histogram, hexbin, regression, qq.
  • Distribution: boxplot, violin, ridgeline, comparison.
  • Financial: candlestick, waterfall, heatmap.
  • Standalone: donut, gauge, treemap, sankey.

Composites

  • boxplot: expands into IQR box + whisker caps + median + outliers.
  • violin: expands into density area + IQR box + median point.
  • ridgeline: density curves stacked vertically by group.
  • regression: scatter + trend line + CI band + R-squared annotation.
  • qq: Q-Q scatter + reference line + confidence envelope.
  • comparison: boxplots + pairwise significance brackets.

Interactions

Infrastructure

  • Responsive sizing that adapts to container dimensions.
  • Shiny integration with myIOOutput() and renderMyIO().
  • Pipe-friendly API using native |>.
  • Theming via CSS custom properties with setTheme().
  • Okabe-Ito colorblind-safe default palette.