Re: st: labels as values of a string variable

[Nick Winter <nw53@cornell.edu>]

I haven't been following this thread, so I don't know why you are trying to 
do this; I suspect htere is a better way.

That said, what's going on here is this.  The line:

    local label`i' = "string[_n]"

is assigning the literal string 'string[_n]' to the local macro label1

But, when you say

    di `label1'

Stata interpets that as

    di string[_n]

and then it displays the contents of string[_n] -- that is, it displays the 
first observation of the variable string.

You will see this if you instead type

    di "`label1'"

which will display the text

    string[_n]

What you need in your original line is this:

    local label`i' = "`=string[_n]'"

In other words, you wrap it in the double quotation marks, to deal with the 
spaces.  But inside the quotes, you surround it with `= and ' , which tell 
stata to evaluate the expression.  This gives you the contents of 
string[_n], rather than the literal string "string[_n]"

All of that said, unless I missed something, the _n in this expression is 
the equivalent of a 1 -- that is, you are just grabbing the first 
observation of each.

Would -encode- do what you want?  Or at least your first approach would 
work as:

   levels string, local(labels)
   tokenize `"`labels'"'

What is your ultimate goal?

--Nick Winter



At 09:41 AM 6/2/2005, you wrote:

> James,
>
> Thanks for your suggestion. Unfortunately it didn't work. The value that I 
> am trying to assign is a string containing space, e.g. "Gross foreign 
> direct investment (% of GDP)". Therefore I have to include the quotation 
> marks (""). In fact the coding I send in my previous email was assigning 
> the string values to the local macros, the problem was when I tried to 
> label the variables using those local macros.
>
> Best,
>
> Rafa
>
> ----- Original Message ----- From: "James Cui" <james.cui@med.monash.edu.au>
> To: <statalist@hsphsun2.harvard.edu>
> Sent: Thursday, June 02, 2005 3:25 PM
> Subject: Re: st: labels as values of a string variable
>
>
>
> > If you change
> > local label`i' = "string[_n]"
> > to
> > local label`i' = string[_n]
> > it should work.
> > The latter assigns the value of string[_n] to label`i'.
> >
> > James.
> >
> >
> > ----- Original Message -----
> > From: "R.E. De Hoyos" <redeho@hotmail.com>
> > Date: Thursday, June 2, 2005 6:54 pm
> > Subject: st: labels as values of a string variable
> >
> > > I want to attach labels to a group of variables (varlist).
> > >
> > > The labels that I want to use for each variable are available as
> > > observations in one of the variables (string). I tried the following:
> > >
> > > levels string, local(labels)
> > > tokenize `lables'
> > >
> > > * An error occurred because the string values contained spaces.
> > > Therefore I
> > > tried:
> > >
> > > egen id = group(string)    //20 groups
> > > local i=1
> > > while `i'<21 {
> > >    preserve
> > >    keep if id==`i'
> > >    local label`i' = "string[_n]"
> > >    local i = `i'+1
> > >    restore
> > > }
> > >
> > > When I used -di `label1'- the label names where correctly
> > > displayed. However
> > > when I tried to attached them to the variables using -label var- :
> > >
> > > label var var1 "`label1'"
> > >
> > > The label attached was "string[_n]" and not the value of it.
> > >
> > > Many thanks,
> > >
> > > Rafa
> > >
> > > ________________________
> > > R.E. De Hoyos
> > > Faculty of Economics
> > > University of Cambridge
> > > CB3 9DE, UK
> > > www.econ.cam.ac.uk/phd/red29
> > > *
> > > *   For searches and help try:
> > > *   http://www.stata.com/support/faqs/res/findit.html
> > > *   http://www.stata.com/support/statalist/faq
> > > *   http://www.ats.ucla.edu/stat/stata/
> > *
> > *   For searches and help try:
> > *   http://www.stata.com/support/faqs/res/findit.html
> > *   http://www.stata.com/support/statalist/faq
> > *   http://www.ats.ucla.edu/stat/stata/
> *
> *   For searches and help try:
> *   http://www.stata.com/support/faqs/res/findit.html
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
--------------------------------------------------------
Nicholas Winter                           607.255.8819 t
Assistant Professor                       607.255.4530 f
Department of Government              nw53@cornell.edu e
308 White Hall            falcon.arts.cornell.edu/nw53 w
Cornell University
Ithaca, NY 14853-4601 
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/