Re: st: Unable to clear "invalid syntax r(197);" error in user-written .ado file

[Richard Herron <richard.c.herron@gmail.com>]

Works like a charm! Thanks for the education, Nick and Joe.

On Fri, Oct 5, 2012 at 5:23 AM, Nick Cox <njcoxstata@gmail.com> wrote:
> Your program accepts -if- and -in-, but does nothing about them.
> -marksample- is the way to do this.
>
> Setting aside the string default issue answered by Joseph, a revised
> program might be something like
>
> program atrim
>      version 11.2
>      syntax varlist(numeric) [if] [in] ///
>          [, Byvar(string) Tail(real 0.5) Suffix(string)]
>
>     quietly {
>
>      marksample touse, novarlist
>      count if `touse'
>      if r(N) == 0 error 2000
>
>     tempvar thisuse pct
>     gen byte `thisuse' = .
>
>      foreach x of local varlist {
>          replace `thisuse'  = `touse' & !missing(`x')
>          bysort `thisuse' `byvar': egen `pct' = rank(`x')
>          bysort `thisuse' `byvar' : replace `pct' = 100 * (`pct' - 0.5) / _N
>          generate `x'_`suffix' = `x' if `thisuse' & inrange(`pct',
> `tail', 100 - `tail')
>          drop `pct'
>      }
>   }
>
>    end
>
> On Fri, Oct 5, 2012 at 3:24 AM, Richard Herron
> <richard.c.herron@gmail.com> wrote:
>> I wrote an .ado file to trim data in the left and right tails, but I
>> can't get past an "invalid syntax r(197)" error. My -syntax- line is
>> as follows.
>>
>> * begin syntax line
>>     syntax varlist(numeric) [if] [in] ///
>>         [, Byvar(string fyear) Tail(real 0.5) Suffix(string tr)]
>> * end syntax line
>>
>> I would like to use a -varlist- so that I can loop over the supplied
>> variables, but I can't clear the error using -varname- or by dropping
>> the -if- and -in- statements. I also tried making the options required
>> without defaults, but that didn't work either.
>>
>> What is my misunderstanding of syntax? Thank you!
>>
>> Below is the complete .ado file. I use Stata SE 11.2 (64 bit) on Windows 7.
>>
>> * begin .ado file
>> *! 0.1 Richard Herron 10/3/2012
>> program atrim
>>     version 11.2
>>     syntax varlist(numeric) [if] [in] ///
>>         [, Byvar(string fyear) Tail(real 0.5) Suffix(string tr)]
>>
>>     * rather than -bysort- twice below
>>     sort `byvar'
>>
>>     * not necessary to tokenize; loop varlist
>>     foreach x of local varlist {
>>
>>         * determine percentiles
>>         by `byvar': egen num = count(`x') if !missing(`x')
>>         by `byvar': egen ran = rank(`x') if !missing(`x')
>>         generate pct = 100 * (ran - 0.5) / num
>>
>>         * replace tails with -sysmiss-
>>         generate test = if inrange(pct, `tail', `=100 - `tail'')
>>         generate `x'_`suffix' = cond(test, `x', .)
>>
>>         * drop "temporary" variables
>>         drop num ran pct test
>>
>>     }
>>
>>     end
>> * end .ado file
> *
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