Coerce a streamline or bundle to a dwiFiber object

as_dwifiber() converts a streamline or bundle to the S4 class dwiFiber from the dti package.

Usage

as_dwifiber(x, ...)

Arguments

x

A streamline or bundle object.

...

Additional arguments (currently unused).

Value

An S4 object of class dwiFiber (from dti).

Details

Per-point direction vectors are taken from @point_data$direction_x, @point_data$direction_y, and @point_data$direction_z when present; otherwise they are estimated via finite differences of the coordinates (forward difference at the first point, backward difference at the last, central differences in between), then unit-normalised.

Bundle-level metadata stored in @bundle_data under the keys method, minfa, maxangle, level, and source are transferred to the corresponding dwiFiber slots when present. Vector-valued fields such as ddim, ddim0, voxelext, and orientation must be stored as individual scalars (e.g. ddim_1, ddim_2, ddim_3) and are reconstructed into vectors for the dwiFiber object.

See also

as_streamline(), as_bundle()

Examples

if (requireNamespace("dti", quietly = TRUE)) {
  sl <- streamline(points = cbind(X = runif(5), Y = runif(5), Z = runif(5)))
  b  <- bundle(streamlines = list(sl))
  dfi <- as_dwifiber(b)
  class(dfi)  # "dwiFiber"
}
#> Warning: RGL: unable to open X11 display
#> Warning: 'rgl.init' failed, will use the null device.
#> See '?rgl.useNULL' for ways to avoid this warning.
#> [1] "dwiFiber"
#> attr(,"package")
#> [1] "dti"