Frame accessors

Generic accessors for the components of an fmri_frame or fmri_view: its assays, active assay, observation and feature axes and IDs, block registries, and dimensions.

Usage

assays(x, ...)

assay(x, name = active_assay(x), ...)

active_assay(x, ...)

observation_axis(x, ...)

observations(x, resolve = FALSE, ...)

features(x, ...)

observation_ids(x, ...)

obs_blocks(x, resolve = FALSE, ...)

feature_blocks(x, ...)

# S3 method for class 'fmri_frame'
dim(x)

nrow.fmri_frame(x)

ncol.fmri_frame(x)

# S3 method for class 'fmri_view'
dim(x)

nrow.fmri_view(x)

ncol.fmri_view(x)

Arguments

x

An fmri_frame or fmri_view.

...

Additional method arguments.

name

Assay name.

resolve

Whether to append reachable, namespaced entity annotations or lazily lifted entity blocks.

Value

assays() returns a named aligned_assay_set list and assay() one aligned_assay from it. active_assay() returns a single assay name. observation_axis() returns an axis_frame; observations() and features() return a data frame of the corresponding metadata. observation_ids() and feature_ids() return character vectors of stable IDs. obs_blocks() and feature_blocks() return named lists of axis_blocks. dim() returns a length-2 integer vector, and nrow() and ncol() return single integers.

Examples

sp <- volume_space(dim = c(2, 2, 2), affine = diag(4))
frame <- fmri_frame(
  assays = list(bold = matrix(rnorm(4 * n_features(sp)), nrow = 4)),
  observations = data.frame(.obs_id = sprintf("vol-%d", 1:4)),
  space = sp
)
names(assays(frame))
#> [1] "bold"
active_assay(frame)
#> [1] "bold"
dim(frame)
#> [1] 4 8