Creates small, deterministic GIFTI and NIML fixtures locally. These files contain 16 vertex rows and four synthetic time points, with no subject data or external downloads. They are licensed under GPL version 2 or later, like the generation code in neurosurf.
Usage
neurosurf_generate_testdata(
files = "all",
destdir = NULL,
overwrite = FALSE,
quiet = FALSE
)
neurosurf_download_testdata(
files = "all",
destdir = NULL,
overwrite = FALSE,
quiet = FALSE
)Arguments
- files
Character vector of fixture names, or
"all". Supported names are"rscan01_lh.gii","rscan01_lh.niml.dset", and"rscan01_rh.niml.dset". The historical names are retained for compatibility; the contents are synthetic, not the former large datasets.- destdir
Existing destination directory. By default, a versioned directory in
tools::R_user_dir("neurosurf", "cache")is created. The installed package directory is never a default destination.- overwrite
Replace existing files? Defaults to
FALSE.- quiet
Suppress progress messages? Defaults to
FALSE.
Details
For the left hemisphere, value \((i,j)\) is \(\sin(i/3) + \cos(j/5)\), for vertices \(i=1,\ldots,16\) and time points \(j=1,\ldots,4\). Right-hemisphere values are the negative of the left values. Node indices in the NIML files are zero-based.
neurosurf_download_testdata() is a compatibility wrapper for this
generator. It no longer downloads the former external test files, whose
redistribution provenance could not be established. Existing files in
an explicitly supplied destination are left unchanged unless
overwrite = TRUE; their original licenses still apply.
Examples
local({
dest <- tempfile("neurosurf-fixtures-")
dir.create(dest)
on.exit(unlink(dest, recursive = TRUE))
paths <- neurosurf_generate_testdata(destdir = dest, quiet = TRUE)
basename(paths)
gifti::readgii(paths[1])$data[[1]][1:3, , drop = FALSE]
})
#> [,1] [,2] [,3] [,4]
#> [1,] 1.307261 1.248256 1.152530 1.023901
#> [2,] 1.598436 1.539431 1.443705 1.315077
#> [3,] 1.821538 1.762532 1.666807 1.538178