help joinvars

Title

joinvars -- Join values of variables

Syntax

joinvars newvar [=] varlist [if] [in] [, options]

update replace non-missing values with non-missing values

missok replace non-missing values with missing values

Description

joinvars creates variable newvar containing joined values of varlist.
Starting with a copy of the first variable in varlist, missing values in newvar
are replaced with values of the next variable(s) in varlist.

Options

Options

update replaces non-missing values in newvar with values of variables
in varlist. Default is to replace missing values only.

missok replaces non-missing values in newvar with missing values of variables
in varlist. May only be specified with update.

Example

First, I separate wages by race in the NLSW 1988 dataset using separate.

. sysuse nlsw88 ,clear
(NLSW, 1988 extract)

. separate wage ,by(race)

[output omitted]

Now suppose the original variable wage is missing in this dataset. It can be created
using joinvars.

. drop wage

. list race wage* in 516/520

+----------------------------------------+
| race wage1 wage2 wage3 |
|----------------------------------------|
516. | white 4.428341 . . |
517. | white 15.09662 . . |
518. | black . 6.843801 . |
519. | other . . 6.513685 |
520. | white 5.072463 . . |
+----------------------------------------+

. joinvars wage = wage1 wage2 wage3

. list race wage1 wage2 wage3 wage in 516/520

+---------------------------------------------------+
| race wage1 wage2 wage3 wage |
|---------------------------------------------------|
516. | white 4.428341 . . 4.428341 |
517. | white 15.09662 . . 15.09662 |
518. | black . 6.843801 . 6.843801 |
519. | other . . 6.513685 6.513685 |
520. | white 5.072463 . . 5.072463 |
+---------------------------------------------------+

The options

. joinvars nonsense = wage1 wage2 wage3 ,update missok

. list race wage1 wage2 wage3 nonsense in 516/520

+---------------------------------------------------+
| race wage1 wage2 wage3 nonsense |
|---------------------------------------------------|
516. | white 4.428341 . . . |
517. | white 15.09662 . . . |
518. | black . 6.843801 . . |
519. | other . . 6.513685 6.513685 |
520. | white 5.072463 . . . |
+---------------------------------------------------+

Author

Daniel Klein, University of Bamberg, klein.daniel.81@gmail.com

Also see

Online: separate, egen, reshape