Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: Dropping min of two consecutive observations


From   "Rijo John" <rmjohn@gmail.com>
To   stata <statalist@hsphsun2.harvard.edu>
Subject   st: Dropping min of two consecutive observations
Date   Thu, 13 Nov 2008 15:33:37 -0600

Dear Statalist,

 I have some repeated observations that I need to drop. I have defined
a unique ID variable. There are two other variables "value" and
"month" for these IDs.

Example data.

ID Value  month
1  25        12
1  22         8
2  30         9
3  28         8
3  24         6


Only few IDs are repeated in the actual data.

Basically I need to retain only one value per ID. If I do "drop if
ID==ID[_n-1]" after sorting the IDs it could drop any of the values.
But I want the data to retain those values where in month takes the
highest value when I am dropping ID==ID[_n-1].  Something like

drop min(month, month[_n-1]) if ID==ID[_n-1] is what I am looking for.
However, I cant use such time series operators with min function. Any
thoughts?

Regards,
Rijo.
*
*   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/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index