| GaussSmoothArray {AnalyzeFMRI} | R Documentation |
Applies a stationary Gaussian spatial smoothing kernel to a 3D or 4D array.
GaussSmoothArray(x, voxdim=c(1, 1, 1), ksize=5, sigma=diag(3, 3), mask=NULL, var.norm=FALSE)
x |
The array to be smoothed. |
voxdim |
The dimensions of the volume elements (voxel) that make up the array. |
ksize |
The dimensions (in number of voxels) of the 3D discrete smoothing kernel used to smooth the array. |
sigma |
The covariance matrix of the 3D Gaussian smoothing kernel. This matrix doesn't have to be non-singular; zero on the diagonal of sigma indicate no smoothing in that direction. |
mask |
A 3D 0-1 mask that delimits where the smoothing occurs. |
var.norm |
Logical flag indicating whether to normalize the variance of the smoothed array. |
The smoothed array is returned.
J. L. Msrchini
d <- c(10, 10, 10, 20) mat <- array(rnorm(cumprod(d)[length(d)]), dim = d) mat[, , 6:10, ] <- mat[, , 6:10, ] + 3 mask <- array(0, dim = d[1:3]) mask[3:8, 3:8, 3:8] <- 1 b <- GaussSmoothArray(mat, mask = mask, voxdim = c(1, 1, 1), ksize = 5, sigma = diag(1, 3))