By default, these generic functions return or replace the "pixdim"
and "pixunits" attributes of their arguments. These represent the
physical step size between pixel or voxel centre points, and the spatial and
temporal units that they are given in. The former defaults to 1 in each
dimension, if there is no attribute.
pixdim(object)
# S3 method for default
pixdim(object)
pixdim(object) <- value
# S3 method for default
pixdim(object) <- value
pixunits(object)
# S3 method for default
pixunits(object)
pixunits(object) <- value
# S3 method for default
pixunits(object) <- value| object | An R object, generally an image. |
|---|---|
| value | Numeric vector of pixel dimensions along each axis, or
character vector of abbreviated units. For dimensions, a scalar
|
pixdim returns a numeric vector of pixel dimensions.
pixunits returns a character vector of length up to two, giving the
spatial and temporal unit names.
Jon Clayden <code@clayden.org>
im <- readNifti(system.file("extdata", "example.nii.gz", package="RNifti"))
pixdim(im)
#> [1] 2.5 2.5 2.5
pixunits(im)
#> [1] "mm" "s"