Skip to content
An R package implementing Stata-like commands for manipulating data
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
R
data
examples
man
.Rbuildignore
.gitignore
DESCRIPTION
LICENSE
NAMESPACE
README.md
rata-manual.pdf
rata.Rproj

README.md

rata: an R package for data manipulation in a Stata-like, "command-on-data" way

Installation

To install rata type, at the R console,

install.packages("devtools", dependencies=TRUE)
library(devtools)
install_github("flynnzac/rata")
library(rata)

Motivation

The goal of this package is to remove one barrier to using R, a free software statistical package, for researchers in the social sciences who are used to Stata's model of data. Stata assumes a rectangular model for data (there are observations and variables) while R allow us for more flexible data structures. There are advantages to R's additional flexibility, but in the social sciences, data is almost always in the (observation, variable) framework, the Stata way of working with data is ingrained, and the additional flexibility of R can make things that are routine in Stata more difficult because the user has to know a much wider variety of functions to get the desired result. This package solves the problem by implementing a Stata-like method for manipulating data in R so that this data model (which I will call the "command-on-data" model) is available in a free software package.

The package implements an environment where there is one active dataset and commands can be used to modify or reference variables from that dataset by issuing "commands" as opposed to R's standard environment (applying functions to modify objects).

To get a feel for what rata looks like see the example in examples/test.r. The syntax is more intuitive (well, hopefully) than standard R to people who are used to thinking at the (observation, variable) level of a dataset.

Current State

I started writing the package on September 20, 2018 so it is very much a work-in-progress, but it should mostly work. Report any bugs or feature requests (if there are features from Stata that you would like to be ported to this environment in R) to the Github repo https://github.com/flynnzac/rata.

rata is a "command-on-data" environment for R and it has a more complete regression package for common models which incorporates robust and clustered standard errors, time series operators, and fixed effects all into one estimation command (this is mostly tying together other R packages which use a function-object interface into a command-on-data interface). The goal is not just to replicate Stata's environment, but to offer an improved command-on-data environment that takes advantage of the additional flexibility of R.

See below for the basic concepts and the reference manual for a list of commands.

Unique rata variable types

Variable lists

Variable lists in rata are specified by quoting the names of variables like, "educ wage black". The names can be specified using wildcard characters as well. For example, if the variables "x100 x2 x3" make up the dataset, they can be all be included by specifying, "x*". If we only want to list "x2 x3", then we can specify "x?" because ? matches only one character.

Quoted Expressions

Many rata commands work by using "quoted expressions" which are bits of code enclosed in quotation marks. For example, to use rata's gen command to generate log wages, you might type gen("lnwage", "log(wage)"). The second argument is a quoted expression. The quotes are necessary so that R does not try to execute log(wage) outside of the rata environment. If you need to use a quotation mark in a quoted expression, escape it like so: gen("hello", "\"hello\"") to generate a variable called hello that contains the string hello for every observation.

Basic overview of currently available functions

Use the use function to load a dataset into the rata environment.

Then, modify the dataset or add additional transformations of variables with the gen command.

Analyze the data using summarize, reg (for linear regression), logit (for binary regression), or execute arbitrary R code in the rata environment (so you can use the variable names directly in the R code) with the do command. You can create a dataset of summary statistics with collapse.

There is support for panel data using xtset (reg works for panel regression as well, see its manual page) and lag can be used to generate lags and leads of variables in the panel.

The data can be reshaped from long-to-wide or from wide-to-long using the shape command.

forvar can apply code by variable to a certain variable list in the dataset.

Licensing

rata is Free Software. It is licensed under version 3 of the GPL. You are free to use, modify, and redistribute the code, but not without restriction. If you produce a modified version of rata, it too must be made available under the terms of the GPL (its source code must be made available and others must also be free to use, modify, and redistribute it). The text of the license is included as the file LICENSE in this repository and at https://www.gnu.org/licenses/gpl-3.0.txt.

You can’t perform that action at this time.