Combine 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.

`append`

Stack two datasets

Stata

append using data2

R Package:dplyr

bind_rows(data1, data2)

Differs from Stata bind_rows() has R type-promotion and attribute rules; .id creates string source identifiers rather than the numeric codes of append, generate().

Stata reference · R reference

1 more examples and alternatives

Stack datasets and record where each row came from

Stata

append using data2, generate(source)

R Package:dplyr

dplyr::bind_rows(data1, data2, .id = "source") |> dplyr::mutate(source = as.integer(source) - 1L)

Differs from Stata Uses numeric source IDs: zero for the master and one for the first using dataset, as Stata append, generate() does. bind_rows() has R type-promotion and attribute rules; .id creates string source identifiers rather than the numeric codes of append, generate().

Stata reference · R reference

`cross`

Every combination of rows from two datasets

Stata

cross using data2

R Package:dplyr

cross_join(data1, data2)

Differs from Stata cross_join() suffixes overlapping column names; Stata cross keeps master values for overlapping names. Rename overlaps first to obtain the same columns.

Stata reference · R reference

`joinby`

All pairs of rows within each id

Stata

joinby id using data2

R Package:dplyr

inner_join(data1, data2, by = "id", relationship = "many-to-many")

Differs from Stata dplyr retains overlapping non-key columns with suffixes instead of Stata master values, creates no _merge, and does not enforce a declared 1:1 key constraint.

Stata reference · R reference

`merge`

Put two datasets side by side by row position

Stata

merge 1:1 _n using data2

R Package:dplyr

bind_cols(data1, data2)

Differs from Stata bind_cols() needs matching row counts (or recyclable one-row inputs) and repairs duplicate names; merge 1:1 _n can retain unmatched rows.

Stata reference · R reference

Merge with a match report

Stata

merge 1:1 id using data2

R Package:tidystata

stata_merge(data1, data2, "1:1", by = "id")

Like Stata, all rows are kept and a .merge column records the match result. full_join(data1, data2, by = “id”) merges without the report.

Stata reference · R reference

One-to-many merge with a match report

Stata

merge 1:m id using data2

R Package:tidystata

stata_merge(data1, data2, "1:m", by = "id")

Stata reference · R reference

Many-to-one merge with a match report

Stata

merge m:1 id using data2

R Package:tidystata

stata_merge(data1, data2, "m:1", by = "id")

Stata reference · R reference

6 more examples and alternatives

Keep all rows of the master data

Stata

merge 1:1 id using data2, keep(master match)

R Package:dplyr

left_join(data1, data2, by = "id")

Differs from Stata dplyr retains overlapping non-key columns with suffixes instead of Stata master values, creates no _merge, and does not enforce a declared 1:1 key constraint.

Stata reference · R reference

Keep rows of data1 whose id is not in data2

Stata

merge 1:1 id using data2, keep(master) keepusing(id) nogenerate

R Package:dplyr

anti_join(data1, data2, by = "id")

Differs from Stata semi_join()/anti_join() select rows by key membership but do not enforce the unique keys required by Stata merge 1:1; validate uniqueness separately.

Stata reference · R reference

Keep matched rows only

Stata

merge 1:1 id using data2, keep(match)

R Package:dplyr

inner_join(data1, data2, by = "id")

Differs from Stata dplyr retains overlapping non-key columns with suffixes instead of Stata master values, creates no _merge, and does not enforce a declared 1:1 key constraint.

Stata reference · R reference

Keep rows of data1 whose id is in data2

Stata

merge 1:1 id using data2, keep(match) keepusing(id) nogenerate

R Package:dplyr

semi_join(data1, data2, by = "id")

Differs from Stata semi_join()/anti_join() select rows by key membership but do not enforce the unique keys required by Stata merge 1:1; validate uniqueness separately.

Stata reference · R reference

Keep all rows of the using data

Stata

merge 1:1 id using data2, keep(using match)

R Package:dplyr

right_join(data1, data2, by = "id")

Differs from Stata dplyr retains overlapping non-key columns with suffixes instead of Stata master values, creates no _merge, and does not enforce a declared 1:1 key constraint.

Stata reference · R reference

Merge on two keys

Stata

merge 1:1 id1 id2 using data2, nogenerate

R Package:dplyr

full_join(data1, data2, by = c("id1", "id2"))

Differs from Stata Variables with the same name in both tables get suffixes; choose them with suffix = c(“_data1”, “_data2”). dplyr retains overlapping non-key columns with suffixes instead of Stata master values, creates no _merge, and does not enforce a declared 1:1 key constraint.

Stata reference · R reference