Generate a Synthetic CSV From a Schema Recipe

Generates a reproducible synthetic data set from the schema$synthetic_recipe block of a provenance object and writes it to a CSV. Columns are produced in declaration order so later columns can reference earlier ones, a shared per-row latent propensity drives any Bernoulli columns, and an optional row-replication block expands per-person rows.

Usage

make_synthetic_csv(schema, out_path, n_rows = NULL, seed = NULL)

Arguments

schema

The synthetic recipe (a list with columns, and optional n_rows, seed, and row_replication) .

out_path

Path where the CSV is written.

n_rows

Number of rows (persons, if replicating) to generate. Defaults to schema$n_rows, then 50000.

seed

Random seed for reproducibility. Defaults to schema$seed, then 91735246.

Value

Invisibly, a list with path, rows (rows written), and seed used.

Examples

recipe <- list(
  n_rows = 20, seed = 42,
  columns = list(
    year   = list(type = "sample", values = list(2024, 2025)),
    alert  = list(type = "bernoulli", p = 0.2),
    visits = list(type = "poisson", lambda = 3, min = 1),
    id     = list(type = "id_pattern", pattern = "p-{seq:05d}")
  )
)
out <- tempfile(fileext = ".csv")
res <- make_synthetic_csv(recipe, out)
res$rows                         # 20
#> [1] 20
res$seed                         # 42 (reproducible)
#> [1] 42

# The written CSV round-trips and has the declared columns.
df <- utils::read.csv(out)
dim(df)
#> [1] 20  4
names(df)
#> [1] "year"   "alert"  "visits" "id"    

# `n_rows` overrides the recipe's own row count.
make_synthetic_csv(recipe, tempfile(fileext = ".csv"), n_rows = 5)$rows
#> [1] 5