generate_nulls: Generate null distributions for brain map data

In neuromapr: Spatial Null Models and Transforms for Brain Map Comparison

Generate null distributions for brain map data

Description

Dispatches to the appropriate null model method for generating spatially-constrained surrogate brain maps.

Usage

generate_nulls(
  data,
  method = c("burt2020", "moran", "spin_vasa", "spin_hungarian", "alexander_bloch",
    "baum", "cornblath", "burt2018"),
  n_perm = 1000L,
  distmat = NULL,
  coords = NULL,
  parcellation = NULL,
  seed = NULL,
  ...
)

Arguments

data	Numeric vector of brain map values.
method	Character string specifying the null model method.
n_perm	Integer number of null permutations to generate.
distmat	Distance matrix (required for "burt2020", "burt2018", and "moran").
coords	List with ⁠$lh⁠ and ⁠$rh⁠ coordinate matrices (required for spin methods).
parcellation	Integer vector of parcel labels (required for "baum" and "cornblath").
seed	Optional integer seed for reproducibility.
...	Additional arguments passed to the specific null method (e.g. rotation for spin methods, kernel for moran/burt2020).

Value

A null_distribution object.

References

Markello RD et al. (2022) Nature Methods 19:1472-1480. doi:10.1038/s41592-022-01625-w

Examples

data <- rnorm(100)
distmat <- as.matrix(dist(seq_len(100)))
nd <- generate_nulls(data, method = "moran", distmat = distmat, n_perm = 10L)

neuromapr documentation built on Feb. 27, 2026, 5:08 p.m.