Thanks a lot for all your inputs - they are really really helpful!
Have a nice weekend!
Robin
On Sat, 26 Feb 2005 06:03:29 -0800 (PST), Gregory Branch
<[email protected]> wrote:
> I haven't spent a lot of time thinking about this, but
> it might be more efficient to take a slightly
> different tack on this. Something like the following
> might work:
>
> 1) Make a second copy of your data set.
> 2) Generate a column of "1"s
> 3) reshape wide, i = year, j = firm, xij = whatever
> you called the column of ones.
> 4) merge back onto the original dataset by year.
>
> Best of luck
>
> Greg Branch
> Research Scientist,
> UT Dallas/Texas Schools Project
>
>
> --- Robin Luo <[email protected]> wrote:
>
> > Sorry for the confusion. Let me explain the
> > situation in more details:
> >
> > I have a variable called "firmid" and I generate a
> > set of dummy
> > variables from it. Now I need to use the value of
> > the varialbe
> > "firmid" to locate the dummy variables and do some
> > calculations but
> > the location part confuses me. Basically, my data
> > has the following
> > structure:
> >
> > firmid year firm_100 firm_101 firm_102
> > firm_103 firm_104 ......
> > 100 1980
> > 101 1980
> > 105 1980
> > 121 1980
> > 124 1980
> > 101 1981
> > 103 1981
> > 196 1981
> >
> > The data has been sorted by year and my goal is to
> > check in each year
> > which firms co-exist with a certain firm - for those
> > coexisting, their
> > respective dummy variables will be changed to 1
> > accordingly. For
> > example, firm 100, 101, 105, 121, 124 coexist in
> > 1980. Therefore, for
> > the record where firmid=100 and year=1980, variables
> > firm_101,
> > firm_105 and likewise will be changed to 1. My plan
> > is that for each
> > year group check the values of "firmid" and then
> > output these values
> > to a local macro, which can be used to locate the
> > corresponding firm
> > dummy variables. But, as stated in my firm mail, I
> > was stuck in how to
> > do this macro set-up in a groupwise environment.
> >
> > Many thanks!
> >
> > Robin Luo
> >
> > On Sat, 26 Feb 2005 00:44:34 +0000, Ada Ma
> > <[email protected]> wrote:
> > > you can't use -by- for setting locals because you
> > can only have one value for
> > > each local value. i can only equals to one thing,
> > it's not like a variable in
> > > the dataset which can carry multiple values.
> > >
> > > what are you trying to do anyway? if you tell us
> > what you're actually trying to
> > > do then may be someone can work out the solution
> > for you.
> > >
> > >
> > > Robin Luo wrote:
> > >
> > > > I know that a command like:
> > > >
> > > > local i = var[`n']
> > > >
> > > > can obtain the nth observation's value into
> > macro i. But my data is a
> > > > panel data and I want the nth observation within
> > a certain group into
> > > > the macro i, instead of that of the nth
> > observation in general.
> > > > Obviously, "local" cannot be used with "by" and
> > I could not figure out
> > > > a way to do this. If any one has any idea on
> > this, I would really
> > > > appreciate.
> > > >
> > > > Thanks!
> > > >
> > > > Robin Luo
> > >
> > > *
> > > * 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/
> > >
> > *
> > * 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/
> >
>
> __________________________________
> Do you Yahoo!?
> Yahoo! Mail - Helps protect you from nasty viruses.
> http://promotions.yahoo.com/new_mail
> *
> * 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/
>
*
* 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/
