This function is used to create extralines (which is an argument of etable) macros
that can be easily summoned in etable.
Details
You can register as many macros as you wish, the only constraint is that the type name should not conflict with a fitstat type name.
Examples
# We register a function computing the standard-deviation of the dependent variable
my_fun = function(x) sd(model.matrix(x, type = "lhs"))
extralines_register("sdy", my_fun, "SD(y)")
# An estimation
data(iris)
est = feols(Petal.Length ~ Sepal.Length | Species, iris)
# Now we can easily create a row with the SD of y.
# We just "summon" it in a one-sided formula
etable(est, extralines = ~ sdy)
#> est
#> Dependent Var.: Petal.Length
#>
#> Sepal.Length 0.6321*** (0.0453)
#> SD(y) 1.765
#> Fixed-Effects: ------------------
#> Species Yes
#> _______________ __________________
#> S.E. type IID
#> Observations 150
#> R2 0.97489
#> Within R2 0.57178
#> ---
#> Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
# We can change the alias on the fly:
etable(est, extralines = list("_Standard deviation of the dep. var." = ~ sdy))
#> est
#> Dependent Var.: Petal.Length
#>
#> Sepal.Length 0.6321*** (0.0453)
#> Fixed-Effects: ------------------
#> Species Yes
#> _______________ __________________
#> S.E. type IID
#> Observations 150
#> R2 0.97489
#> Within R2 0.57178
#> Standard deviation of the dep. var. 1.765
#> ---
#> Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1