scan.dti.tract.file: Scan a tract file without holding its data in memory.

In freesurferformats: Read and Write 'FreeSurfer' Neuroimaging File Formats

Scan a tract file without holding its data in memory.

Description

Streams through the tract file and either counts the tracts, or computes the bounding box of all their points, or both. Nothing but the current chunk is ever held in memory, so this works on files of any size.

Usage

scan.dti.tract.file(filepath, want = c("count", "bbox"), 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.
want	character vector, any combination of 'count' and 'bbox'.
chunk_values	integer, number of payload values to read per chunk.

Value

named list with the entries that were requested: count (integer, the number of tracts) and bbox (numeric vector of length 6, c(xmin, xmax, ymin, ymax, zmin, zmax)), or NULL for bbox if no point was found.

freesurferformats documentation built on Sept. 25, 2026, 1:07 a.m.