look for -egen-, substr()
I think the command you're looking for would be:
egen icd_9=substr(icd_10, 1, 3)
> Dear Statalists,
>
> I want to generate a newvar icd_9 with only the firt 3 letters from oldvar
> icd_10.
>
> icd_10 icd_9
> B51.0 B51
> B51.8 B51
> B52.0 B52
> B52.8 B52
> B52.9 B52
> ..... .....
> This can be done in EXCEL with LEFT command line e.g: left(B51.9, 3)=B51
> But I don't know how to do it in Stata(8) Command
>
> Any help will be appreciated
>
> Many thanks in advance.
>
> Dr. Ha Thai Son
> NIMPE Hanoi, Vietnam
>
> *
> * For searches and help try:
> * http://www.stata.com/support/faqs/res/findit.html
> * http://www.stata.com/support/statalist/faq
> * http://www.ats.ucla.edu/stat/stata/
>
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
