cluster.shell.alpha: Compute the alpha value of a cluster shell.

In fsbrain: Managing and Visualizing Brain Surface Data

Compute the alpha value of a cluster shell.

Description

The shells of a cluster are more transparent the closer they are to the threshold, and fully opaque at the highest level of their sign.

Usage

cluster.shell.alpha(level, threshold, levels, alpha_range = c(0.08, 1))

Arguments

level	single number, the iso-level of the shell.
threshold	single positive number, the cluster threshold.
levels	numerical vector of all iso-levels, see volume.cluster.levels.
alpha_range	numerical vector of length 2, the alpha value of the outermost and the innermost shell.

Value

single number between 0 and 1, the alpha value of the shell.

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