write.nii.volume {nifti.io}

Write NIfTI-1 Volume

Description

Write values to a specific volume in a NIfTI-1 file.

Usage

  write.nii.volume(nii.file, vol.num, values)

Arguments

nii.file

Full directory listing to a NIfTI file. File must not be gzipped.

vol.num

An integer indicating which volume to read.

values

an array or vector of values to be written

Details

NIfTI files need to be unzipped before using this function or any other portions of the nifti.io package. This is necessary given the inconsistent way in which gzipped files are indexed.

Value

Output directly to NIFTI file.

Author(s)

Timothy R. Koscik <[e-mail]>

Examples

# get filename for example NII file included in nifti.io package
ref.nii <- system.file("extdata", "egBrain.nii", package="nifti.io")

# create a temporary file to write into
tdir <- tempdir()
new.nii <- paste0(tdir, "/new.nii")
init.nii(new.nii = new.nii, ref.nii = ref.nii)

# generate an array of random values the same size as the image volume
xyz.dims <- info.nii(ref.nii, "xyz")
new.values <- array(rnorm(prod(xyz.dims)), dim=xyz.dims)

# write out volume all at once
write.nii.volume(nii.file = new.nii, vol.num = 1, values = new.values)