This is not to me a simple question as you don't spell out fully what is
going on.
I guess that you have a variable number of trades on each day. In that
situation, the mean over trades and the mean over days (the mean of
daily means) will probably differ.
If you want a mean over trades, that would be easiest got by
. summarize trade
And if you want that in a variable (difficult to see why), you could
then go
. gen trademeantot = r(mean)
Your second statement is equivalent, but a bit inefficient. Still, by
the time you have typed two commands not one, you wouldn't notice.
If you want a mean over days, each day being given equal weight, then
you could go
egen tag = tag(date)
su trademean if tag
and if necessary
gen trademeantot = r(mean)
Nick
[email protected]
Beatrice Crozza
maybe again a simple question, but I tried to read the help and I
didn't find a solution.
I have calculated a daily mean for my variable trade, typing:
egen trademean=mean(trade), by(date)
now I want to calculate the total mean, so I typed:
egne trademeantot=mean(trademean)
but I don't think that the result is correct.
Do you have any idea of how to calculate a mean, taking into account
the daily mean?
*
* 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/
