Expand an in-memory cohort and attach pre-computed inverse-probability weights, returning the weighted frame as a data.frame — the frame-in/frame-out analogue of expand_weighted_parquet().

Both the cohort and the per-(id, period) factor table (id, period, weight_factor) are passed as R data.frames; the engine expands under estimand, joins the factors, and accumulates the cumulative-product weight. A 64-bit integer id (bit64::integer64) in either frame round-trips exactly.

Usage

expand_weighted_df(
  cohort,
  factors,
  id_col,
  period_col,
  treatment_col,
  eligible_col,
  outcome_col,
  first_period,
  last_period,
  estimand
)

Arguments

cohort

An R data.frame of long person-time rows.

factors

An R data.frame with columns id, period, weight_factor.

id_col, period_col, treatment_col

Column names in cohort.

eligible_col, outcome_col

Eligibility / outcome column names.

first_period, last_period

Inclusive integer bounds on trial_period.

estimand

"ITT" or "PP". Case-insensitive.

Value

A data.frame with the six structural columns plus weight. Errors in the core engine surface as R errors.