Using Levelsof return to rename Column

[Kevin Ribot]

Dear all,

Im trying to rename column based on levelsof return function :
I tried

levelsof varName if exp

it returns “‘myValue’” and then I want to achieve this

rename col1 _this returned value_

its not working, I guess because it returns kind of a string value ? Has anyone any idea how to achieve that.

Regards,
Kevin

[Clyde Schechter]

I'm not sure I follow what you want to do, but it sounds like it might be this:

levelsof varName if exp, local(returned_values)
local new_var_name: word 1 of `returned_values'
rename col1 `new_var_name'

There are a few cautions about this. First, if exp != 0 does not define a unique observation in your data set, then -levelsof- will return several different values. The above code assumes you intend to use the first of those. But you need to think through how you actually want to handle that situation. Another problem is that varName, unless it is actually populated with names of variables, might contain something that is not a legal variable name in Stata, and if that happens, the -rename- command will, of course, fail. So if you encounter that problem, then what you want to do is not possible at all. You can, however, come close by doing it this way:

levelsof varName if exp, local(returned_values)
local new_var_name: word 1 of `returned_values'
local new_var_name = strtoname(`"`new_var_name'"')
rename col1 `new_var_name'

The -strtoname()- function takes a string argument and returns the same string with all characters that are illegal in a Stata variable name replaced by underscore (_) characters.