Captures data once into a shared data reference and returns an inert
simtab_spec. Printing the returned object shows the analysis plan; it never
performs estimation.
Examples
spec <- simtab(epitabl)
spec
#> <simtab_spec>
#> not yet computed
#> data: 1500 rows x 22 columns; hash c0787c425db7
#> describe: <unset>
#> stratify/by: <unset>
#> adjust: <unset>
#> summary: auto
#> measure: <unset> (ref: <unset>, conf.level: 0.95)
#> test: <unset>
#> design: <unset>
#> style: default