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Re: st: 2 questions on function wordcount
From
Nick Cox <[email protected]>
To
[email protected]
Subject
Re: st: 2 questions on function wordcount
Date
Thu, 3 May 2012 17:59:31 +0100
To spell this out (the number 6 here is just the number of variables
in a currently open Stata)
. unab vlist : *
. di `: word count `vlist''
6
. di c(k)
6
i.e. note also that the number of variables in memory is directly
accessible in c(k). So, this is a one way to do it in this case
. di "`: word `c(k)' of `vlist''"
group
More generally
. local k `: word count `vlist''
. di "`: word `k' of `vlist''"
The last could be telescoped into one line, with some cost in readability.
Note that the limit that bites here is not on macro length, but on the
length of string in a string expression.
Nick
On Thu, May 3, 2012 at 5:39 PM, Austin Nichols <[email protected]> wrote:
> Gregorio <[email protected]>:
> wordcount() will truncate the string at 255 characters. Instead use
> -local- tricks described at
> help extended_fcn
On Thu, May 3, 2012 at 12:34 PM, Impavido, Gregorio <[email protected]> wrote:
>> The following two examples should give the same result but they don't.
>>
>> /*-------begin 1 ---------*/
>> unab vlist : *
>> di wordcount(`"`vlist'"')
>> /*-------end 1 ---------*/
>>
>> /*-------begin 2 ---------*/
>> unab vlist : *
>> local i 0
>> foreach var of local vlist {
>> local i = `i' + 1
>> }
>> di `i'
>> /*-------end 2 ---------*/
>>
>> In my case, wordcount gives me a different result depending on how I rename the variables in the dataset while the second gives me always 170 (which happens to be the number of variables in the dataset.
>>
>> Question 1. Is this related to the length limitation of the local macro? But if Yes, why is the macro vlist not truncated?
>>
>> Question 2. Is there a quicker way to do display the last word in vlist (i.e., -di word((`"`vlist'"',wordcount(`"`vlist'"'))-) than using example 2 above to extract the number of the last variable?
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