write_epoch_parquet: Write flat epoch-level Parquet output

In GGIR: Raw Accelerometer Data Analysis

Write flat epoch-level Parquet output

Description

Builds a flat epoch-level table from meta/ms5.outraw time-series data and writes it as a Parquet file. This is a legacy/compatibility export pathway; the preferred dashboard export is write_dashboard_parquet.

Usage

write_epoch_parquet(
  metadatadir = c(),
  params_output = c(),
  params_general = c(),
  params_phyact = c(),
  verbose = TRUE
)

Arguments

metadatadir	Directory that holds a folder 'meta' and inside this a folder 'ms5.outraw' which contains the milestone data produced by g.part5. The folder structure is normally created by g.part5 and GGIR will recognise what the value of metadatadir is.
params_output	See details in GGIR.
params_general	See details in GGIR.
params_phyact	See details in GGIR.
verbose	See details in GGIR.

Details

This function uses build_epoch_table to read and harmonize epoch-level data (one row per epoch), then applies type coercions and writes results/parquet/ggir_epochs.parquet.

Metadata stored in the Parquet footer includes export type, creation timestamp, selected ms5 configuration name, acceleration metric, and estimated epoch length in seconds.

This export path is mainly useful for workflows that prefer a separate flat epoch table rather than nested epochs inside the dashboard parquet.

Value

Invisibly returns the written Parquet file path, or NULL (invisibly) when export is skipped.

Author(s)

Samuel Timileyin Afolabi <[e-mail]>

See Also

GGIR, build_epoch_table, write_dashboard_parquet

Examples

## Not run: 
write_epoch_parquet(
  metadatadir = "path/to/output_run/output_test_run",
  params_output = list(),
  params_general = list(desiredtz = "", acc.metric = "ENMO"),
  params_phyact = list(part6_threshold_combi = "40_100_400"),
  verbose = TRUE
)

## End(Not run)

GGIR documentation built on Nov. 9, 2026, 1:07 a.m.