as.sparse: Convert to from dense to sparse representation

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

Convert to from dense to sparse representation

Description

Convert to from dense to sparse representation

Usage

as.sparse(x, mask, ...)

Arguments

x	the object to make sparse, e.g. DenseNeuroVol or DenseNeuroVec
mask	the elements to retain
...	additional arguments

Details

mask can be an integer vector of 1D indices or a mask volume of class LogicalNeuroVol

Examples

bvol <- NeuroVol(array(runif(24*24*24), c(24,24,24)), NeuroSpace(c(24,24,24), c(1,1,1)))
indmask <- sort(sample(1:(24*24*24), 100))
svol <- as.sparse(bvol, indmask)


mask <- LogicalNeuroVol(runif(length(indmask)), space=space(bvol), indices=indmask)
sum(mask) == 100

bbuchsbaum/neuroim2 documentation built on Jan. 2, 2025, 3:38 p.m.