Ambiguous abbreviation with $

[Franzi De]

Hi there,

I hope this question is not too basic - I'm working with some do files created by someone else for a number of older datasets and am supposed to be making them work for the newer versions. I'm stumbling upon this:

merge 1:1 variable1 variable2 using "${path}pl.dta", keepusing($pl) keep(match master) nogen

First of all, I don't think I fully understand what the $ does within the keepusing() command. From googling it seems this usually has to do with a global macro, but I'm not sure that makes sense in this context.

When I run this, I get an "ambiguous abbreviation" error. Consequently, the same thing happens with the next command:

use variable1 variable2 $pl using "${path}pl.dta", clear

"variable3 ambiguous abbreviation"

Can someone please help with this?

Thanks in advance,
Franzi

[daniel klein]

My guess is $pl is a global macro that contains variable names or abbreviations of variable names. One or more of those do not uniquely identify a variable in the dataset pl.dta.

You can type

display "$pl"

or

macro list

to view the contents of the global macro.

You should be able identify the offending contents with

use ${path}pl.dta
foreach varname of global pl {
    capture noisily confirm variable `varname'
}

[Franzi De]

My guess is $pl is a global macro that contains variable names or abbreviations of variable names. One or more of those do not uniquely identify a variable in the dataset pl.dta.

You are right, I found pl where the macros are defined in the do file. I think the problem might be that global pl is interpreted as global plot because pl is an abbreviation for plot? Hence, Stata might think that $pl is an abbreviation for something. Is that a possibility? If yes, how can I fix that if I can't change the name of the dataset?

edit: sorry, I just realized that there are actually different variables in the data set and the command was indeed ambiguous due to that - I was wrong as I thought the problem is with the name of the dataset and not the variable. Sorry!

[daniel klein]

No need for apologies.

For the record:

I think the problem might be that global pl is interpreted as global plot because pl is an abbreviation for plot? H

cannot be the problem because you cannot abbreviate global macro names. In fact, you can only abbreviate commands, options, and variable names.

[Stephen Jenkins]

Abbreviating variable names is a recipe for disaster in my opinion (e.g., sometimes code will run even though it's in error and you don't realise it). I -set var abbrev off- in my profile.do to avoid problems.