substituteWaveletCoef: Substitute 2D wavelet transform coefficients with user-given...

In BHMSMAfMRI: Bayesian Hierarchical Multi-Subject Multiscale Analysis of Functional MRI (fMRI) Data

Substitute 2D wavelet transform coefficients with user-given values

Description

substituteWaveletCoef substitutes the wavelet coefficients stored wavelet object generated through 2D wavelet transform with user-given values and returns the modified wavelet object.

Usage

substituteWaveletCoef(grid, waveletobj, values)

Arguments

grid	The number of voxels in one row (or, one column) of the brain slice of interest. Must be a power of 2. The total number of voxels is grid^2. The maximum value of grid for this package is 512.
waveletobj	A wavelet object of class imwd.object, usually obtained by performing 2D wavelet transformion through the function imwd of package wavethresh.
values	The values with which the wavelet coefficients are to be replaced. The order should be consistent with imwd.object class.

Details

The maximum value of grid for this package is 512.

Value

A wavelet object of class imwd.object with updated wavelet coefficients.

Author(s)

Nilotpal Sanyal, Marco Ferreira

Maintainer: Nilotpal Sanyal <[e-mail]>

See Also

imwd

Examples

set.seed(1)
n <- 3
grid <- 8
ntime <- 10
designmat <- cbind( rep(1,10), c(rep(c(1,0),5)) )
data <- array(dim=c(n,grid,grid,ntime),
  rnorm(n*grid*grid*ntime))
glm.fit <- glmcoef(n, grid, data, designmat)
glmcoefstd <- glm.fit$GLMCoefStandardized[,,,1]
dwt = wavethresh::imwd(glmcoefstd[1,,],type="wavelet",
  family="DaubLeAsymm",filter.number=6,bc="periodic")
dwt

values = rnorm(grid^2-1)
dwtnew = substituteWaveletCoef(grid,dwt,values)
dwtnew

BHMSMAfMRI documentation built on Oct. 2, 2022, 9:05 a.m.