Threshold.RF: Random Field Theory Thersholds.

In AnalyzeFMRI: Functions for Analysis of fMRI Datasets Stored in the ANALYZE or NIFTI Format

Description

Calculates the Random Field theory threshold to give that results in a specified p-value.

Usage

Threshold.RF(p.val, sigma, voxdim = c(1, 1, 1), num.vox,
             type = c("Normal", "t"), df = NULL)

Arguments

p.val	The required p-value.
sigma	The 3D covariance matrix of the random field.
voxdim	The dimesnions of a voxel.
num.vox	The number of voxels that constitute the random field.
type	The type of random field, "Normal" or "t".
df	The degrees of the t distributed field.

Details

Calculates the threshold that produces an expected Euler characteristic equal to the required p-value.

Value

Returns the Random Field threshold.

Author(s)

J. L. Marchini

See Also

EC.3D

Examples

a <- Threshold.RF(p.val = 0.05, sigma = diag(1, 3), voxdim = c(1, 1, 1), num.vox = 10000)

EC.3D(a, sigma = diag(1, 3), voxdim = c(1, 1, 1), num.vox = 10000)

AnalyzeFMRI documentation built on Oct. 5, 2021, 5:06 p.m.