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Changelog

Source: NEWS.md

ggseg (development version)

A major release. The atlas geometry now comes from the re-keyed ggseg.formats atlases (>= 0.0.4.9008), and geom_brain() has been rebuilt on a Stat so that faceting, inherited data/aes(), and outline aesthetics work the way ggplot2 users expect. Several of those fixes change existing figures, so read the breaking changes before upgrading.

Breaking changes

  • Region keys changed. ggseg.formats re-keyed the bundled atlases: the region column now holds short keys (e.g. "superiorparietal", "transversetemporal") and the fully spelled-out names moved to a new names column. Any user data joined to an atlas by region must be re-keyed. Passing a long name where a region is expected no longer matches, and geom_brain() warns that the rows were not merged. ggseg.formats ships a helper for translating old keys to new — look for legacy_region_map() in the ggseg.formats reference — or join by the schema-stable label column instead. ggseg now requires ggseg.formats (>= 0.0.4.9008); the combination of an older ggseg with the re-keyed atlases is silently wrong, which the new floor rules out.

  • GeomBrain is a different object. Both 2.2.1 and 3.0.0 export GeomBrain, but it is no longer the same ggproto: it is now the polygon geom (GeomBrain < ggplot2::GeomPolygon < ggplot2::Geom) that backs the default geom_brain(). The sf geom it used to be is now GeomBrainSf, which this release also exports so extension code doing ggplot2::layer(geom = GeomBrain) against the sf path has a migration target: switch to GeomBrainSf. Because the export name did not change, the failure mode in extension code is a confusing rendering error rather than an object-not-found error — check any package that reaches for GeomBrain directly.

  • geom_brain() gained a fun argument, positionally before show.legend. The signature is now geom_brain(mapping, data, atlas, hemi, view, position, context, fun, show.legend, inherit.aes, ...). Callers passing show.legend or inherit.aes positionally shift by one — name those arguments.

  • Multiple data rows per region are now combined, not overplotted. fun (default mean) reduces them within each facet panel. Long data with several rows per region — one per subject, say — used to overplot, so the last row silently won; it is now averaged. This is a silent numeric change for anyone plotting an unaggregated cohort, so geom_brain() warns once per session when fun actually collapses rows. Pass fun = dplyr::last to recover the old last-wins behaviour. fun applies to numeric columns only — non-numeric columns take the first value of the group regardless.

  • aes() mappings for x, y, group, and subgroup are ignored, with a warning. They are derived from the atlas geometry (group is the polygon feature id, subgroup marks holes), so mapping them previously corrupted the rendering silently — aes(group = region) collapsed each region’s separate polygon pieces.

  • Polygon draw order now follows your data’s row order. It used to be the atlas’s own polygon order regardless of your data, so when you mapped a variable to colour the outlines stacked in an order unrelated to it. Regions now draw in the order they appear in your data (later rows on top); regions you supply no value for stay underneath in atlas order. arrange() your data to control layering. Visual-only, but it restacks overlapping outlines (#162).

  • position_brain() ignores the hemi term for slice-based atlases (subcortical, cerebellar, tract), with a warning. Those views are whole slices already containing both hemispheres, so hemi ~ view no longer splits the grey context into its own row away from the structures. Each view now renders with its anatomical context integrated, matching plot(). Subcortical and tract plots using hemi ~ view lay out differently (correctly).

New features

  • New stat_brain() and exported StatBrain ggproto: the stat-first spelling of geom_brain(). Both build the same layer; use stat_brain() to pair StatBrain with a different geom.

  • New brain_test_plot() builds a minimal, deterministic atlas plot (regions filled by label, no legend, theme_void()) — the canonical construction for vdiffr snapshots across the ggsegverse, so a stray legend or title cannot creep into a snapshot and every atlas renders identically. It defaults to position_brain(. ~ view) for slice-based atlases and position_brain(hemi ~ view) for cortical ones.

  • GeomBrainSf is now exported (see above).

Bug fixes

  • A bare geom_brain() again colours the atlas by its palette, keyed on label — unchanged from 2.2.1. The default is now installed at build time, so a top-level aes(fill = value) wins instead of erroring with “Continuous value supplied to a discrete scale”.

  • Faceting no longer needs dplyr::group_by(). The atlas geometry is drawn by StatBrain, which ggplot2 recomputes per panel, so facet_wrap() / facet_grid() work directly from your data. Faceting on a variable of your own draws the complete brain in every panel; faceting on an atlas column (hemi, view) draws that slice in each panel, as before.

  • geom_brain() again respects data and aesthetics set in the top-level ggplot() call. The polygon renderer built the atlas eagerly, before the plot existed, so it never saw inherited data/aes() (#158).

  • geom_brain() again maps aes(colour = ...) and aes(linewidth = ...) to region outlines. The defaults (grey35, 0.2) were injected as fixed geom parameters, which silently overrode any mapping; they are now default_aes on GeomBrain (#160).

  • geom_brain() again warns when rows of your data match no atlas region. The polygon renderer’s left join dropped unmatched rows silently (#121).

  • scale_x_brain(), scale_y_brain() and scale_labs_brain() no longer require the optional sf package. They derived their axis breaks by converting the atlas to sf and reading coordinates back out, so on a system without sf they errored instead of working – even though sf moved to Suggests in 2.2.0 and everything else on the default path had been made sf-free. They now read the coordinates from the polygon representation (ggseg.formats::atlas_polygons()). The breaks and labels are unchanged for dk(), aseg() and tracula(); a test pins them to the sf-derived values.

  • geom_brain(position = ) again applies a layout string or formula. Previously only a position_brain() spec took effect; everything else, including an invalid value, was silently dropped. Strings and formulas are now coerced, "identity" opts out, and anything else errors.

  • Axis scales work for cerebellar atlases such as suit(). adapt_scales() returned NULL for any type outside cortical/subcortical/tract, so scale_x_brain() and friends produced empty scales. Unsupported types now error.

  • scale_continous_brain() no longer returns a scale without breaks at its default aesthetics = c("y", "x"); the argument was matched after it was used.

  • position_brain(hemi ~ view, nrow = 2) now errors instead of silently discarding the formula, and nrow/ncol must be positive whole numbers (ncol = 0 produced Inf grid indices). The deprecated position_brain_sf() and reposition_brain() validate the same way, and before their sf guard, so a bad argument is not reported as a missing sf.

  • A nrow/ncol grid on a cortical atlas now gives each hemisphere/view pair its own cell; it split on view alone, putting both hemispheres in every cell.

  • position_brain(views = ) warns when a named view is not in the atlas, and zoom = warns when a named region is not, instead of silently dropping it. zoom = TRUE resolves its focus from label before region, and a named focus may use either vocabulary.

  • A layout formula variable containing a dot (e.g. my.col ~ view) is no longer dropped along with the . placeholder.

  • annotate_brain() accepts a layout string or formula without requiring the optional sf; it routed every non-spec position into the sf implementation.

  • scale_brain() and friends error with the available atlas names when name is not an atlas; match.fun() resolved any visible function.

  • The deprecated scale_*_brain() scales warn at build time when no mapped value is a palette key. Atlas palettes are keyed by label, so aes(fill = region) drew every region in na.value with no signal.

  • Laying out a data frame that mixes atlas types now errors with an explanation rather than R’s “condition has length > 1”.

Documentation and internals

  • Roxygen documentation now uses markdown.

  • positioning-views.Rmd used region and view names no atlas has ("Thalamus Proper", coronal_3), so three zoom figures and two view-selection figures demonstrated nothing.

  • Tests, examples, and vignettes resolve region names dynamically through ggseg.formats::atlas_regions() and the schema-stable label column instead of hard-coding region strings.

  • vdiffr snapshots are keyed by atlas schema through testthat’s variant mechanism, so one snapshot set per ggseg.formats schema can be committed side by side.

  • The test helpers no longer attach Suggests packages unconditionally, so the suite degrades to skips rather than erroring under _R_CHECK_DEPENDS_ONLY_=true.

ggseg 2.2.1

CRAN release: 2026-07-03

  • The test suite now builds its sf fixtures through the public atlas accessors instead of reaching into atlas internals, so tests no longer break when the internal atlas layout changes.

ggseg 2.2.0

CRAN release: 2026-06-22

This release makes the sf package optional. ggseg now draws brains from a lightweight polygon representation by default, so it installs and plots even on systems where sf (and its GDAL / GEOS / PROJ system libraries) is unavailable — including WebAssembly and air-gapped setups.

sf is now optional

New plotting features

  • Zoom in on regions of interest. position_brain(zoom = ...) crops each view onto the regions you’re highlighting so they fill the panel, with the surrounding brain reduced to a tidy grey frame. Use zoom = TRUE to follow the regions in your data, or name them explicitly; zoom_pad sets the margin. Especially handy for focus atlases where only a few structures carry values.
  • Readable view labels. annotate_brain() now places labels clear of the brain instead of on top of it. The new padding argument (5% of the plot height by default) controls the gap.
  • One annotation function. annotate_brain() works with whichever position you gave the geom — there’s no separate labelling function to remember.
  • Hide context regions. geom_brain(context = FALSE) drops the grey, unlabelled regions and tightens the layout around the regions you’re plotting.
  • Faceting. Group your data with dplyr::group_by() and facet_wrap() / facet_grid() draw the full atlas in every panel.
  • FreeSurfer labels. Data keyed by label (e.g. "lh_bankssts") now joins to the atlas directly, in addition to region.

Other changes

  • When no fill is mapped, geom_brain() fills regions with the atlas’s own colours, and the stray “No shared levels” warning that appeared when filtering by hemisphere or view is gone.
  • New coord_brain() keeps brain proportions undistorted; geom_brain() applies it automatically, so you rarely need to add it yourself.
  • The deprecated scale_brain() family keeps working with the current ggseg.formats.
  • The suit cerebellar atlas is re-exported alongside dk(), aseg(), and tracula().

ggseg 2.1.1

CRAN release: 2026-04-16

  • Fix minor bug with ggproto

ggseg 2.1.0

CRAN release: 2026-04-03

  • Support cerebellar atlas type in 2D view stacking. Cerebellar atlases now use the same stacking layout as subcortical atlases in position_brain().

ggseg 2.0.0

CRAN release: 2026-02-19

This is a major release that simplifies the package architecture by moving atlas data structures and utilities to the ggseg.formats package.

Breaking changes

New features

  • New annotate_brain() function adds view labels (e.g., “left lateral”) to brain plots, respecting the layout from position_brain().

  • New scale_brain_manual() family for applying custom named colour palettes to brain plots.

  • position_brain() gains nrow, ncol, and views arguments for grid-based layout control of subcortical and tract atlases.

  • adapt_scales() now accepts atlas objects directly (not just pre-converted coordinate data frames), and handles "tract" atlas types alongside subcortical.

  • geom_brain() now automatically applies the atlas colour palette when no fill aesthetic is mapped.

Improvements

  • Messaging uses cli for all user-facing output (brain_join() warnings and info messages).

  • Rewrote and reorganised all vignettes with updated examples and renamed files for cleaner URLs.

  • Added tracula (white matter tract) atlas as a re-export from ggseg.formats.

  • Improved documentation throughout with updated roxygen2 docs.

ggseg 1.6

ggseg 1.6.8

  • Increased C++ standard to C++17 to comply with CRAN policies

ggseg 1.6.7

  • Fixed testthat issues with latest version of testthat
  • Fixed vignette build issues on CRAN
  • removed sf minimum version requirement

ggseg 1.6.5

  • Bump version to 1.6.5
  • rm freesurfer dep
  • rm old remnants
  • update readme img
  • switch cerebellum labels for wm, gm, fix #80
  • fix aseg labels to original, fix #78
  • add vis as categorical. fix #76
  • change aseg data class , fix #56
  • bump version, small CRAN fixes
  • add sysreq
  • fix axial to coronal in vignette
  • change axial to coronal in aseg data
  • re-add ggplot2 depends

1.6.4

  • Added options hemi and side to geom
  • improved position_brain() to accept character vector, and also support subcortical atlases
  • Altered axial to coronal in aseg atlas

1.6.3.01

  • fixed broken geom after changes to ggplot2 internals
  • fixed spelling mistakes in docs

ggseg 1.6.3

  • removed function to display ggseg palettes
  • preparations for CRAN submission
    • added examples to more functions
    • updated links

ggseg 1.6.02

  • bug fixes in atlas objects and method internals
  • tests in vdiffr
  • vctrs class for polygon ggseg data

ggseg 1.6.02

  • No longer depends on ggplot2, but imports it.
    • as is advised practice
    • users must explicitly load ggplot2 to access further ggplot2 functions

ggseg 1.6.01

  • fixed installation issues by making sure package depends on R>3.3 for polygon holes.

ggseg 1.6.00

New large update, many new features. Of particular note is the introduction of the brain sf geom, which improved speed, and adaptability of the plots.

  • ggseg() will stay for a while, but is superseded by a simple features geom
  • geom_brain introduced as a new function to plot the atlas data
    • an sf geom provides a lot of new features to the package
    • more control over display of the slices through position_brain()
    • improved capabilities for atlases with regions that have holes
  • new atlas class brain_atlas which contains simple features data
  • new functions to allow compatibility between sf and polygon data
  • utility functions to use on the atlas data for easy access to information
    • plot() functions for ggseg_atlas and brain_atlas classes for a quick look at atlases
    • brain_regions functions to easily extract the unique names of regions for an atlas
    • improved print method for atlases classes ggseg_atlas and brain_atlas

ggseg 1.5

ggseg 1.5.5

  • dk atlas regions renamed to better reflect correct naming
    • pre central and post central are precentral and postcentral
  • dk atlas now also includes the corpus callosum, as the original atlas contains

ggseg 1.5

ggseg 1.5.4

  • dkt renamed to dk
    • the dkt (Desikan-Killiany-Tourville) atlas is not yet available
  • atlas columns area renamed to region
    • to avoid confusion with the calculation of cortical/surface area
  • dk atlas region name “medial orbito frontal” changed to “medial orbitofrontal”

ggseg 1.5.3

  • Split ggseg, and ggseg3d into two different packages

ggseg 1.5.2

  • Adapted to work with dplyr 0.8.1

ggseg 1.5.1

  • Changed ggseg_atlas-class to have nested columns for easier viewing and wrangling

ggseg 1.5

  • Changed atlas.info to function atlas_info()

  • Changed brain.pal to function brain_pal()

  • Changed atlas.info to function atlas_info()

  • Reduced code necessary for brain_pals_info

  • Simplified display_brain_pal()

  • Moved palettes of ggsegExtra atlases to ggsegExtra package

  • Added a NEWS.md file to track changes to the package.

  • Added compatibility with grouped data.frames

  • Reduced internal atlases, to improve CRAN compatibility

  • Added function to install extra atlases from github easily

  • Changes vignettes to comply with new functionality