Discover Derivative Datasets

Finds derivative datasets (fMRIPrep, MRIQC, etc.) available for an OpenNeuro dataset. Searches both embedded derivatives within the dataset and external derivatives from the OpenNeuroDerivatives GitHub organization.

Usage

on_derivatives(
  dataset_id,
  sources = c("embedded", "openneuro-derivatives"),
  refresh = FALSE,
  client = NULL
)

Arguments

dataset_id

Dataset identifier (e.g., "ds000102").

sources

Character vector specifying which sources to check. Default is c("embedded", "openneuro-derivatives") to check both. Use "embedded" for derivatives stored within the dataset, or "openneuro-derivatives" for external derivatives from GitHub.

refresh

If TRUE, bypass cache and fetch fresh data from APIs. Default is FALSE to use cached results when available.

client

An openneuro_client object for embedded derivative checks. If NULL (default), creates a default client.

Value

A tibble with one row per available derivative, containing:

dataset_id

The dataset identifier

pipeline

Pipeline name (e.g., "fmriprep", "mriqc")

source

Where the derivative is from: "embedded" or "openneuro-derivatives"

version

Pipeline version (NA if not available)

n_subjects

Number of subjects processed (NA if not available)

n_files

Number of derivative files (NA if not available)

total_size

Human-readable size (e.g., "2.3 GB", NA if not available)

last_modified

Last modification time (POSIXct, NA if not available)

s3_url

S3 URL for OpenNeuroDerivatives sources (NA for embedded)

Returns an empty tibble with the same structure if no derivatives are found.

Details

Derivative Sources

Embedded derivatives are stored directly within the dataset's BIDS structure in a derivatives/ subdirectory. These are typically provided by the dataset authors.

OpenNeuroDerivatives are externally processed derivatives maintained by the OpenNeuro team, available from the OpenNeuroDerivatives GitHub organization. These are stored on S3 and can be downloaded separately.

Source Preference

When the same pipeline exists in both sources, embedded derivatives are preferred and the OpenNeuroDerivatives entry is removed from results. This follows the principle that author-provided derivatives should take precedence.

Caching

Results are cached per-session to minimize API calls. Use refresh = TRUE to bypass the cache and fetch fresh data.

See also

on_files() for listing files within datasets

Examples

if (FALSE) { # \dontrun{
# Find all derivatives for a dataset
derivs <- on_derivatives("ds000102")
print(derivs)

# Check only OpenNeuroDerivatives (GitHub)
github_derivs <- on_derivatives("ds000102", sources = "openneuro-derivatives")

# Check only embedded derivatives
embedded_derivs <- on_derivatives("ds000102", sources = "embedded")

# Force refresh of cached data
fresh_derivs <- on_derivatives("ds000102", refresh = TRUE)

# Filter for fMRIPrep derivatives
fmriprep <- derivs[derivs$pipeline == "fmriprep", ]
} # }