The aim of statable is to enable you to combine the strengths of both R and Stata into one seamless workflow. This document introduces you to statable’s basic functionality.
To start using statable, you must first load the package.
Note: All statable functions start with the prefix
stata_.
Finding Stata
In order to run, statable needs the path to your Stata executable. It
should find this path automatically, but if it cannot you can specify it
using stata_path(). This function may also be useful if you
have multiple versions of Stata installed and want to run an older
version.
# For example on Windows
stata_path("C:/Program Files/Stata18/StataSE-64.exe")
# or on Mac
stata_path("/Applications/Stata/StataSE.app/Contents/MacOS/stata-se")
# or on Linux
stata_path("/opt/stata18/stata-mp")Running Commands
To run a Stata command from R, simply use the
stata_run() function. You can pass a single Stata command
to this function or a vector of commands.
See how the second set of commands used the auto dataset
that we loaded with the first command. This works because, by default,
stata_run() uses the same Stata session every time you run
a command. This means all your data and results stay in one place,
allowing you to easily build on your previous commands. If needed, you
can also run multiple Stata sessions at the same time but most users can
use statable without worrying about session management.
Transferring Data
Functions
statable makes it is easy to transfer datasets between R and Stata. This is useful when you want to use Stata’s powerful statistical capabilities on data that you initially cleaned and tidied in R.
To pass data from R to Stata, use the function
stata_data_in(). This function takes an R data frame and
sends it to the Stata session that you are working with. Behind the
scenes, stata_data_in() exports the R data frame to a
.dta file using the haven::write_dta
function.
Similarly, if you have been working with a dataset in Stata and want
to bring that data back into R, use the function
stata_data_out(). This function retrieves the current
dataset from the active Stata session and returns it as a data
frame.
data("mtcars")
stata_data_in(mtcars, clear = TRUE)
stata_run("summarize")
stata_run("rename mpg miles_per_gallon")
mtcars_stata <- stata_data_out()
mean(mtcars_stata$miles_per_gallon)Magic Macros
In addition to these direct data transfer functions, statable
provides a more general way to work with data between R and Stata using
global macros. In Stata, global macros of the form
$R_dataframe_name are used to reference R data frames. When
you create a global macro in this format, statable automatically exports
the specified R data frame to a .dta file, which is the
file format used by Stata for datasets. The value of the global macro is
then set to the path of this .dta file.
This functionality allows you to seamlessly use R data frames with a
variety of Stata commands that require a path to a dataset, such as
merge, joinby, or append. For
example, in the following code, $R_mtcars references the R
data frame called mtcars in Stata, allowing you to
use it and then append it.
# statable sets the gloal R_mtcars to be equal to the path of a dta file
# containing the data frame mtcars.
stata_run("use $R_mtcars, clear")
stata_run("summarize")
stata_run("display _N")
stata_run("append using $R_mtcars")
stata_run("display _N")Note: R allows both variable names and column names to have dots in them but this is not allowed by Stata. You will have to rename them first.