Construct data

Start with the expanded example for each command. Open the variants for options and alternative R approaches. Read the qualifications before adapting the code.

expand

Repeat each row n times

Stata

expand n

R tidyr

uncount(data, n)

Differs from Stata uncount() drops n afterwards; add .remove = FALSE to keep it. uncount() drops the count column by default and zero counts remove rows; Stata expand keeps the count variable and retains observations when the count is below one.

Stata reference · R reference

fillin

Add rows for every combination of values

Stata

fillin x1 x2

R tidyr

complete(data, x1, x2)

Differs from Stata expand(data, x1, x2) returns only the combinations; expand_grid(x1 = 1:5, x2 = c(“a”, “b”)) builds them from scratch. complete() adds combinations without the _fillin indicator created by Stata fillin; factor levels and missing-key combinations also need explicit decisions.

Stata reference · R reference

input

Type in a small dataset

Stata

input x y

R tibble

tibble(x = c(1, 2), y = c(3, 4))

Stata reference · R reference

set

Start a dataset with a given number of rows

Stata

set obs 100

R tibble

data <- tibble(id = 1:100)

Stata reference · R reference