Download long.dta 

(see “Stata format” under “Files used in the examples”)

// Import the “long” dataset

use "long.dta", clear

list

     +--------------------------------------------------+

     | First   Last     Type   Group   Age        Plant |

     |--------------------------------------------------|

  1. |  John   Sims   Veggie       A    30    Artichoke |

  2. |  Mary   Sims   Veggie       A    25    Asparagus |

  3. |  John   Kent   Veggie       A    40              |

  4. |  John   Sims   Veggie       B    30     Broccoli |

  5. |  Mary   Sims   Veggie       B    25              |

     |--------------------------------------------------|

  6. |  John   Kent   Veggie       B    40              |

  7. |  John   Sims   Veggie       C    30       Carrot |

  8. |  Mary   Sims   Veggie       C    25       Celery |

  9. |  John   Kent   Veggie       C    40              |

 10. |  John   Sims    Fruit       A    30        Apple |

     |--------------------------------------------------|

 11. |  Mary   Sims    Fruit       A    25      Apricot |

 12. |  John   Kent    Fruit       A    40      Avocado |

 13. |  John   Sims    Fruit       B    30       Banana |

 14. |  Mary   Sims    Fruit       B    25              |

 15. |  John   Kent    Fruit       B    40    Blueberry |

     |--------------------------------------------------|

 16. |  John   Sims    Fruit       C    30       Cherry |

 17. |  Mary   Sims    Fruit       C    25    Cranberry |

 18. |  John   Kent    Fruit       C    40   Clementine |

     +--------------------------------------------------+

Transform using reshape

// In Stata the transformation from Long to Wide is a two step process.

/* Reshape Wide:

* Create the wide form of the data where the “Plant” variable is broken into two separate columns according to the levels of “Type” specified in “j” (i.e., Veggie and Fruit).

* Specify variable(s) that uniquely identify (i) each observation (First, Last, Group).

* Specify “string” because Type is a string variable.

*/

reshape wide Plant, i(First Last Group) j(Type) string

// Optional: rename variables

rename PlantFruit Fruit

rename PlantVeggie Veggie

// Optional: gsort, order

gsort Group -Last First

order Age Veggie Fruit, after(Group)

list    

     +-----------------------------------------------------+

     | First   Last   Age   Group      Veggie        Fruit |

     |-----------------------------------------------------|

  1. |  John   Sims    30       A   Artichoke        Apple |

  2. |  Mary   Sims    25       A   Asparagus      Apricot |

  3. |  John   Kent    40       A                  Avocado |

  4. |  John   Sims    30       B    Broccoli       Banana |

  5. |  Mary   Sims    25       B                          |

     |-----------------------------------------------------|

  6. |  John   Kent    40       B                Blueberry |

  7. |  John   Sims    30       C      Carrot       Cherry |

  8. |  Mary   Sims    25       C      Celery    Cranberry |

  9. |  John   Kent    40       C               Clementine |

     +-----------------------------------------------------+

/* Reshape Wide:

* Create the wide form of variables by combining Type and Group categories, where Group names (A, B, C) are given a prefix based on Type (Veggie or Fruit).

* Specify variable(s) that uniquely identify (i) each observation (First, Last, Type).

* Specify “string” because Type is a string variable.

*/  

reshape wide Veggie Fruit, i(First Last) j(Group) string

// Optional: order

order VeggieA-VeggieC FruitA-FruitC, after(Age)

list

     +----------------------------------------------------------------------------------------+

     | First   Last   Age     VeggieA    VeggieB   VeggieC    FruitA      FruitB       FruitC |

     |----------------------------------------------------------------------------------------|

  1. |  John   Kent    40                                    Avocado   Blueberry   Clementine |

  2. |  John   Sims    30   Artichoke   Broccoli    Carrot     Apple      Banana       Cherry |

  3. |  Mary   Sims    25   Asparagus               Celery   Apricot                Cranberry |

     +----------------------------------------------------------------------------------------+