Create a square region of interest — square

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
#> [1] TRUE