st: Re: reverse variable order

[Kit Baum <baum@bc.edu>]

To somewhat simplfy Maarten's code (without the check for x following  
a strict pattern, which in fact is not required in this approach),  
see below

On Jul 17, 2007, at 2:33 AM, Maarten wrote:


> *---------- begin example --------------
> sysuse auto, clear
> forvalues i = 1/10 {
> 	gen x`i' = uniform()
> }
>
> unab vars : x*
// this places the list of x* variables in macro vars

. mata

: v=tokens(st_local("vars"))

: v2=invtokens(v[cols(v)..1])

: st_local("revvars",v2)

:
: v2
  x10 x9 x8 x7 x6 x5 x4 x3 x2 x1

: end
------------------------------------------------------------------------ 
--------

. di "`revvars'"
x10 x9 x8 x7 x6 x5 x4 x3 x2 x1

// Back in Stata, the local macro revvars now contains the reversed  
list of x variables. No need to loop. -order- can be applied to this  
list (prepended with the list of non-x variables, extracted as  
Maarten illustrates).

Kit 
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