volume.cluster.extremes: Compute the highest iso-level per sign.

In fsbrain: Managing and Visualizing Brain Surface Data

Compute the highest iso-level per sign.

Description

Computes the highest absolute iso-level for the positive and the negative clusters, i.e., the level of the innermost shell of a cluster. If max_level is NULL, the max_level_quantile quantile of the absolute values beyond the threshold is used, so that a single extreme voxel does not dominate the visualization.

Usage

volume.cluster.extremes(
  volume,
  threshold,
  max_level = NULL,
  max_level_quantile = 0.99,
  positive = TRUE,
  negative = TRUE
)

Arguments

volume	a 3D numerical array.
threshold	single positive number, the cluster threshold.
max_level	single positive number or NULL, the highest level given by the user.
max_level_quantile	single value between 0 and 1, the quantile used to compute the highest level if max_level is NULL.
positive	logical, whether to consider the positive clusters.
negative	logical, whether to consider the negative clusters.

Value

named numerical vector with the entries 'neg' and 'pos' (the highest absolute iso-level of the negative and of the positive clusters), or NA for a sign that has no voxels beyond the threshold (or was not requested).

fsbrain documentation built on Sept. 27, 2026, 1:07 a.m.