Read DTI tracking per-coord data from file in MRtrix 'TSF' format.

Reads per-vertex track scalars from a TSF file, optionally gzip-compressed.

Usage

read.dti.tsf(
  filepath,
  max_tracks = Inf,
  skip_tracks = 0L,
  chunk_values = 4e+06
)

Arguments

filepath

character string, path to the TCK or TSF file to read. Gzip-compressed files (i.e., .tck.gz) are supported and the compression is detected from the file content, not the file name.

max_tracks

numeric, the maximum number of tracks to read. Use Inf (the default) to read all tracks. This allows reading a subset of a very large tractogram without holding all of it in memory.

skip_tracks

integer, the number of tracks to skip before reading any. Skipped tracks are never held in memory.

chunk_values

integer, the number of payload values that are read per chunk. This is an advanced tuning parameter that does not change the result, only the peak memory usage (at most one chunk is buffered at a time) and the granularity of the file reads. The default of 4e6 values corresponds to about 32 MB of doubles. Lower it on a machine with very little free memory.

Value

named list with entries 'header' and 'scalars'. The scalar data are available in 3 representations: 'merged' (a vector of all values), 'lengths' (the number of values per track) and 'scalar_list' (a list of vectors, one per track, which is expensive for large files and should be avoided for whole-brain data in favour of 'merged' and 'lengths').

Examples

if (FALSE) { # \dontrun{
tsff <- "~/simple.tsf"
tsf <- read.dti.tsf(tsff)
} # }