position_brain: Alter brain atlas position

In ggseg: Plotting Tool for Brain Atlases

Alter brain atlas position

Description

Function to be used in the position argument in geom_brain to alter the position of the brain slice/views.

Usage

position_brain(position = "horizontal", nrow = NULL, ncol = NULL, views = NULL)

Arguments

position	Formula describing the rows ~ columns organisation for cortical atlases (e.g., 'hemi ~ view'). For subcortical/tract atlases, can be "horizontal", "vertical", or a formula with 'type ~ .' where type is extracted from view names like "axial_1" -> "axial".
nrow	Number of rows for grid layout. If NULL (default), calculated automatically. Only used for subcortical/tract atlases when position is not a formula.
ncol	Number of columns for grid layout. If NULL (default), calculated automatically. Only used for subcortical/tract atlases when position is not a formula.
views	Character vector specifying which views to include and their order. If NULL (default), all views are included in their original order. Only applies to subcortical/tract atlases.

Value

a ggproto object

Examples

library(ggplot2)

# Cortical atlas with formula
ggplot() +
  geom_brain(
    atlas = dk(), aes(fill = region),
    position = position_brain(. ~ view + hemi),
    show.legend = FALSE
  )

ggplot() +
  geom_brain(
    atlas = dk(), aes(fill = region),
    position = position_brain(view ~ hemi),
    show.legend = FALSE
  )


ggplot() +
  geom_brain(
    atlas = aseg(), aes(fill = region),
    position = position_brain(nrow = 2)
  )

ggplot() +
  geom_brain(
    atlas = aseg(), aes(fill = region),
    position = position_brain(
      views = c("sagittal", "axial_3", "coronal_2"),
      nrow = 1
    )
  )

ggplot() +
  geom_brain(
    atlas = aseg(), aes(fill = region),
    position = position_brain(type ~ .)
  )

ggseg documentation built on April 3, 2026, 5:06 p.m.