Re: st: Batch renaming variables

[Maarten Buis <maartenlbuis@gmail.com>]

The one thing that may be a bit tricky is that the Mata function
numtobase26() is undocumentend. It basically maps positive integers to
letters such that 1=A, 2=B, ..., 26=Z, 27=AA, 28=AB, ..., 52=AZ,
53=BA, 54=BB, etc.

-- Maarten

On Thu, Oct 18, 2012 at 4:39 PM, Nick Cox <njcoxstata@gmail.com> wrote:
> Maarten and I really used the same method, just in part implemented it
> differently.
>
> Your problem is easy to understand, but awkward to solve without
> knowing about loops and some macro manipulations.
>
> On Thu, Oct 18, 2012 at 3:34 PM, Wameq Raza <wameq.r@gmail.com> wrote:
>> Dear Maarten and Nick,
>> Thank you very much and I'll certain discuss the problem from the
>> outset! The method laid out
>> by Maarten worked like a charm! I'll have to spend a little more time
>> understanding the syntax
>> better, but my problem for now is definitely solved.
>> Many thanks once again,
>> Best
>> Wameq
>>
>> On Thu, Oct 18, 2012 at 4:28 PM, Maarten Buis <maartenlbuis@gmail.com> wrote:
>>> On Thu, Oct 18, 2012 at 4:03 PM, Wameq Raza wrote:
>>>> The variables I have start from v0915 and continue to v1005 and I need
>>>> to rename every 5th variable in this list starting from v0917. The
>>>> variables to be renamed to are: cost_a, cost_b....cost_n.
>>>
>>> *--------------------------- begin example --------------------------
>>> // create some example data
>>> clear
>>> set obs 10
>>> forvalues i = 915/1005 {
>>>         gen v`:display %04.0f `i'' = runiform()
>>> }
>>>
>>> // start renaming
>>> local j = 0
>>> forvalues i = 917(5)1005 {
>>>         local j = `j' + 1
>>>         mata: st_local("letter", strlower(numtobase26(strtoreal(st_local("j")))))
>>>         rename v`:display %04.0f `i'' cost_`letter'
>>> }
>>> *---------------------------- end example ---------------------------
>>>
> *
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-- 
---------------------------------
Maarten L. Buis
WZB
Reichpietschufer 50
10785 Berlin
Germany

http://www.maartenbuis.nl
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