<>
As [U], p. 145, says: " Observe that the relational operator for equality is
a pair of equal signs. This convention distinguishes relational equality
from the =exp assignment phrase."
The -bysort- statement in my earlier post is probably redundant, given that
Stata did not complain about any lack of it when the relational operator ">"
was used, but it certainly won`t hurt you. You can always -describe- your
data to see whether they are already sorted by any variable...
HTH
Martin
-----Ursprüngliche Nachricht-----
Von: [email protected]
[mailto:[email protected]] Im Auftrag von amatoallah
ouchen
Gesendet: Freitag, 18. September 2009 23:06
An: [email protected]
Betreff: st: about the command by
good day stata listers
Sorry for the question, but I''m getting stuck on some very simple matter,
I'want to compute the number of observations with the condition Rt=0
by country and by years
so when I' ve put
. by country years: count if rt=0
i've got the message: exp not allowed
whereas when I've put
by country years: count if rt<0 and by country years: count if rt>0
there is no trouble
I'm really puzzled
thanks a lot in in advance!!!!
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
