Subset an fs.tracts instance.
Examples
if (FALSE) { # \dontrun{
tck <- read.dti.tck("brain.tck");
first_ten <- tck$tracks[1:10];
} # }
Subset an fs.tracts instance.
if (FALSE) { # \dontrun{
tck <- read.dti.tck("brain.tck");
first_ten <- tck$tracks[1:10];
} # }