square_roi: Create a square region of interest

In bbuchsbaum/neuroim2: Data Structures and IO for Neuroimaging Data with an Emphasis on Functional Magnetic Resonance Imaging (FMRI)

Create a square region of interest

Description

This function creates a square region of interest (ROI) in a 3D volume, where the z-dimension is fixed at one voxel coordinate. The ROI is defined within a given NeuroVol or NeuroSpace instance.

Usage

square_roi(bvol, centroid, surround, fill = NULL, nonzero = FALSE, fixdim = 3)

Arguments

bvol	A NeuroVol or NeuroSpace instance representing the 3D volume or space.
centroid	A numeric vector of length 3, representing the center of the square ROI in voxel coordinates.
surround	A non-negative integer specifying the number of voxels on either side of the central voxel.
fill	An optional value or values to assign to the data slot of the resulting ROI. If not provided, no data will be assigned.
nonzero	A logical value indicating whether to keep only nonzero elements from bvol. If bvol is a NeuroSpace instance, this argument is ignored.
fixdim	A logical value indicating whether the fixed dimension is the third, or z, dimension. Default is TRUE.

Value

An instance of class ROIVol representing the square ROI.

Examples

sp1 <- NeuroSpace(c(10, 10, 10), c(1, 1, 1))
square <- square_roi(sp1, c(5, 5, 5), 1)
vox <- coords(square)
## a 3 X 3 X 1 grid
nrow(vox) == 9

bbuchsbaum/neuroim2 documentation built on April 20, 2024, 4:20 p.m.