freesurferformats (version 1.1.0)

fs.tracts: Create an fs.tracts instance from a compact tract representation.

Description

Creates the compact container used by the DTI tract readers and writers. Reading a track file with read.dti.tck, read.dti.trk or read.dti.tsf returns instances of this class, and this function is the way to build one from your own data, e.g., to write a tractogram that was assembled or edited in R with write.dti.tck or write.dti.trk.

Usage

fs.tracts(coords, lengths, scalars = NULL, properties = NULL, kind = "tck")

Value

an fs.tracts instance.

Arguments

coords

numeric matrix with 3 columns, the concatenated coordinates of all tracts.

lengths

integer vector, the number of points of each tract. Must sum up to nrow(coords).

scalars

numeric matrix or NULL. Per-point data, with one row per point (i.e., nrow(scalars) == nrow(coords)).

properties

numeric matrix or NULL. Per-tract data, with one row per tract.

kind

character string, either 'tck' or 'trk'. Determines what [[ returns for a single tract.

Examples

# Two tracts, the first with two points and the second with one.
coords <- matrix(c(0, 0, 0, 1, 1, 1, 5, 5, 5), ncol = 3, byrow = TRUE);
tracts <- fs.tracts(coords, lengths = c(2L, 1L));
length(tracts);
tracts[[1]];