Mike Frone wrote:
I obtained data in this form:
respnum_ injnum finalwt2 gender ir1 ir2 ir3_ ir4_1_
354 1 16151.351 male yes 2 no no
354 2 16151.351 male yes 2 yes no
354 3 16151.351 male yes 2 . .
354 4 16151.351 male yes 2 . .
354 5 16151.351 male yes 2 . .
However, because this person only experienced 2 injuries, I wanted the
data in this form:
respnum_ injnum finalwt2 gender ir1 ir2 ir3_ ir4_1_
354 1 16151.351 male yes 2 no no
354 2 16151.351 male yes 2 yes no
How can I keep the number of records for a given respondent equal to the
number of injuries experienced?
----------------------------------------------------
I responded:
Assuming that ir3_ and ir4_1_ are 0/1 numeric variables, no/yes being
the
value labels:
drop if ir3==0 & ir4_1_==0
- but this was nonsense; it should have been:
drop if ir3 >= . & ir4_1_ >= .
-----------------------------------------------------
Mike responded to my nonsense suggestion
Thanks for your response. Unfortunately, as I noted, this was a partial
record for one case. There are many other injury characteristics.
Moreover, a respondent may have from 1 to 5 injury event, so the number
of
records within each value of respnum_ can range from 1 to 5. So a
simple
drop is unlikely to resolve the problem.
-----------------------------------------------------
I guess that you can identify "empty" observations, i.e. observations
not representing an injury, by one or more variables having a missing
value. That is the aim of
drop if ir3 >= . & ir4_1_ >= .
Svend
__________________________________________
Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(Institute of Public Health, Department of Epidemiology)
Vennelyst Boulevard 6
DK-8000 Aarhus C, Denmark
Phone: +45 8942 6090
Home: +45 8693 7796
Email: [email protected]
__________________________________________
*
* 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/
