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Re: st: Difference of values in the same column/variable
From
Tirthankar Chakravarty <[email protected]>
To
[email protected]
Subject
Re: st: Difference of values in the same column/variable
Date
Wed, 23 Nov 2011 18:37:52 -0800
You have a panel setup and for error-free handling in cases like this,
use Stata's -xt- machinery:
*****************************************
clear*
input group str7 time ewportret
1 2007m4 .0375245
1 2007m5 .0397919
1 2007m6 -.0188678
0 2007m4 .041679
0 2007m5 .0449738
0 2007m6 -.0240277
end
g time2 = monthly(time, "YM")
format time2 %tm
xtset group time2
g dewportret = D.ewportret
li
*****************************************
T
On Wed, Nov 23, 2011 at 6:23 PM, Anna Reimondos <[email protected]> wrote:
> Hi Gokhan
> Maybe something like
>
>
> gen newvar=.
> gsort time -group
> bysort time: replace newvar=ewportret-ewportret[_n+1] if group==1 &
> group[_n+1]==0
>
> Or in a loop
>
> gen newvar=.
> forvalues n=1/6 {
> replace newvar=ewportret-ewportret[`n'] if time==time[`n'] & group==1
> }
>
>
> Anna
>
>
> On Tue, Nov 15, 2011 at 1:21 PM, <[email protected]> wrote:
>> Dear All,
>>
>> How can i create a new variable that is equal to the difference in ewportret
>> (see below table) between two groups in the same month?
>> For example: the first row of the newvar below would be equal to (.0375245-
>> .041679) and the second row would be equal to(.0397919- .0449738)
>>
>>
>> group time ewportret newvar
>>
>> 1 2007m4 .0375245
>> 1 2007m5 .0397919
>> 1 2007m6 -.0188678
>> 0 2007m4 .041679
>> 0 2007m5 .0449738
>> 0 2007m6 -.0240277
>>
>>
>> Thank you
>>
>> Gokhan
>>
>>
>> *
>> * 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/
>
--
Tirthankar Chakravarty
[email protected]
[email protected]
*
* 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/