spherical_roi: Create a Spherical Region of Interest

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

Create a Spherical Region of Interest

Description

Creates a Spherical ROI based on a centroid.

Usage

spherical_roi(
  bvol,
  centroid,
  radius,
  fill = NULL,
  nonzero = FALSE,
  use_cpp = TRUE
)

Arguments

bvol	an NeuroVol or NeuroSpace instance
centroid	the center of the sphere in positive-coordinate (i,j,k) voxel space.
radius	the radius in real units (e.g. millimeters) of the spherical ROI
fill	optional value(s) to store as data
nonzero	if TRUE, keep only nonzero elements from bvol
use_cpp	whether to use compiled c++ code

Value

an instance of class ROIVol

Examples

 sp1 <- NeuroSpace(c(10,10,10), c(1,2,3))
 # create an ROI centered around the integer-valued positive voxel coordinate: i=5, j=5, k=5
 cube <- spherical_roi(sp1, c(5,5,5), 3.5)
 vox <- coords(cube)
 cds <- coords(cube, real=TRUE)
 ## fill in ROI with value of 6
 cube1 <- spherical_roi(sp1, c(5,5,5), 3.5, fill=6)
 all(cube1 == 6)

 # create an ROI centered around the real-valued coordinates: x=5, y=5, z=5
 vox <- coord_to_grid(sp1, c(5, 5, 5))
 cube <- spherical_roi(sp1, vox, 3.5)

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