stata-tidy

This is a basic implementation of the tidyr package from R.

gather

gather transforms a wide dataset into a long dataset (i.e. reshape long). The command takes a list of variables as argument. This list corresponds to variables to gather. Use the option label to save the variable labels as a new variable.

sysuse educ99gdp.dta, clear
list in 1/5

     +------------------------------+
     |   country   public   private |
     |------------------------------|
  1. | Australia       .7        .7 |
  2. |   Britain       .7        .4 |
  3. |    Canada      1.5        .9 |
  4. |   Denmark      1.5        .1 |
  5. |    France       .9        .4 |
     +------------------------------+

gather public private
list in 1/10

     +------------------------------+
     |   country   variable   value |
     |------------------------------|
  1. | Australia     public      .7 |
  2. | Australia    private      .7 |
  3. |   Britain     public      .7 |
  4. |   Britain    private      .4 |
  5. |    Canada     public     1.5 |
     |------------------------------|
  6. |    Canada    private      .9 |
  7. |   Denmark     public     1.5 |
  8. |   Denmark    private      .1 |
  9. |    France     public      .9 |
 10. |    France    private      .4 |
     +------------------------------+

gather public private is equivalent to:

rename public _1
rename private _2
reshape long _, i(country) j(variable) string
rename _ value

spread

spread transforms a long dataset into a wide dataset (i.e. reshape wide). The command takes two variable names as argument. The first variable contains the new variable names. The second variable contains the new variable values.

list in 1/5

     +------------------------------+
     |   country   variable   value |
     |------------------------------|
  1. | Australia     public      .7 |
  2. | Australia    private      .7 |
  3. |   Britain     public      .7 |
  4. |   Britain    private      .4 |
  5. |    Canada     public     1.5 |
     +------------------------------+

spread variable value
list in 1/5

     +------------------------------+
     |   country   private   public |
     |------------------------------|
  1. | Australia        .7       .7 |
  2. |   Britain        .4       .7 |
  3. |    Canada        .9      1.5 |
  4. |   Denmark        .1      1.5 |
  5. |    France        .4       .9 |
     +------------------------------+

spread variable value is equivalent to:

reshape wide value, i(country) j(variable) string
rename value* *

unite

unite pastes together multiple variables into one.

gen var1 = "a"
gen var2 = "b"
unite var1 var2, gen(var3)
list in 1/3

     +--------------------+
     | var1   var2   var3 |
     |--------------------|
  1. |    a      b    a_b |
  2. |    a      b    a_b |
  3. |    a      b    a_b |
     +--------------------+

Installation

tidy is available on SSC.

ssc install tidy

To install the latest version from Github:

net install tidy, from("https://raw.githubusercontent.com/matthieugomez/stata-tidy/main/")