Load experiment from database

Reconstructs a PhysioExperiment object from database records.

Usage

loadExperiment(con, experiment_id, load_signals = FALSE)

Arguments

con

A DuckDB connection.

experiment_id

The experiment identifier.

load_signals

If TRUE, loads signal data from chunks.

Value

A PhysioExperiment object.

References

Raasveldt M, Muehleisen H (2019). "DuckDB: an embeddable analytical database." Proceedings of the 2019 International Conference on Management of Data (SIGMOD). doi:10.1145/3299869.3320212

See also

registerExperiment, queryExperiments, deleteExperiment

Examples

# DuckDB is an optional dependency; guard the example so it only runs
# when the package is installed.
if (requireNamespace("duckdb", quietly = TRUE)) {
  tf <- tempfile(fileext = ".duckdb")
  con <- connectDatabase(tf)
  initPhysioSchema(con)
  pe <- PhysioExperiment(
    assays = list(raw = matrix(0, nrow = 100, ncol = 3)),
    colData = S4Vectors::DataFrame(label = c("Fp1", "Fp2", "Cz")),
    samplingRate = 256
  )
  registerExperiment(con, pe, experiment_id = "demo1",
    subject_id = "sub01", task = "rest", store_signals = TRUE)
  # Reconstruct the object, with signal data
  pe2 <- loadExperiment(con, "demo1", load_signals = TRUE)
  disconnectDatabase(con)
  unlink(tf)
}
#> duckdb keeps downloaded extensions and secrets in a temporary directory:
#> ℹ /tmp/Rtmpa6DD5K/duckdb
#> This is removed when the R session ends.
#> • Extensions are re-downloaded each session.
#> • Secrets are lost.
#> ℹ Run duckdb(shared_home = TRUE) (or create ~/.duckdb) to keep them (suitable for most users).
#> ℹ Run duckdb(shared_home = FALSE) to accept the temporary directory (and silence this message).
#> ℹ See ?duckdb_storage for details and alternatives.