This is similar to model.frame, but is designed specifically
for panel_data() data frames. It's a workhorse in wbm()
but may be useful in scripting use as well.
Arguments
- formula
A formula. Note that to get an individual-level mean with incomplete data (e.g., panel attrition), you should use
imean()rather thanmean().- data
A
panel_data()frame.
Value
A panel_data() frame with only the columns needed to fit
a model as described by the formula.
Examples
data("WageData")
wages <- panel_data(WageData, id = id, wave = t)
model_frame(lwage ~ wks + exp, data = wages)
#> # Panel data: 4,165 × 5
#> # Entities: id [595]
#> # Wave variable: t [1, 2, 3, ... (7 waves)]
#> id t lwage wks exp
#> <fct> <dbl> <dbl> <dbl> <dbl>
#> 1 1 1 5.56 32 3
#> 2 1 2 5.72 43 4
#> 3 1 3 6.00 40 5
#> 4 1 4 6.00 39 6
#> 5 1 5 6.06 42 7
#> 6 1 6 6.17 35 8
#> 7 1 7 6.24 32 9
#> 8 2 1 6.16 34 30
#> 9 2 2 6.21 27 31
#> 10 2 3 6.26 33 32
#> # ℹ 4,155 more rows