Re: st: check if string or numeric

[Richard Goldstein <richgold@ix.netcom.com>]

check the help file for -ds-

Rich

Jacob Wegelin wrote:
> I would like to check for type of variable (string, numeric, etc) in a 
> program, and then take action on the basis of the type. For instance, if 
> it's string, I encode it; else I leave it as is.
>
> The following klugey program seems to solve the problem *part of the 
> time*. But certainly there is a more elegant way?
>
> capture program drop checkIfString
> program define checkIfString, rclass
>     di "check if `1' is string or numeric"
>     quietly tabulate `1'
>     local NobsRegardlessOfStringOrNumeric=r(N)
>     quietly summarize `1'
>     local NobsOnlyIfNumeric=r(N)
>     di "NobsRegardlessOfStringOrNumeric: 
> `NobsRegardlessOfStringOrNumeric' and NobsOnlyIfNumeric: 
> `NobsOnlyIfNumeric'"
>
>     if (`NobsRegardlessOfStringOrNumeric'>0) & ( 
> `NobsRegardlessOfStringOrNumeric'  == `NobsOnlyIfNumeric' ) {
>             return local type="numeric"
>         }
>
>     else {
>
>         if (`NobsRegardlessOfStringOrNumeric'>0) & ( 
> `NobsOnlyIfNumeric'==0 ) {
>                 return local type="string"
>             }
>
>     else {
>             return local type="not sure"
>             }
>
>     }
> end
>
> clear
> set obs 5
> gen x=_n
> gen y="a"
> gen z=.
> gen w=""
>
> list
>
> checkIfString x
> return list
> checkIfString y
> return list
> checkIfString z
> return list
> checkIfString w
> return list
>
>
> This seems like a FAQ but I haven't found the answer yet on the Web.
>
> Thanks for any tips
>
> Jake
>
> Jacob A. Wegelin
> jwegelin@vcu.edu Assistant Professor
> Department of Biostatistics
> Virginia Commonwealth University
> 730 East Broad Street Room 3006
> P. O. Box 980032
> Richmond VA 23298-0032
> U.S.A. http://www.people.vcu.edu/~jwegelin
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