Another comment is quite different. If
this example is your problem, you probably
would benefit considerably by using -reshape-
to get a long structure.
Nick
[email protected]
> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]]On Behalf Of Nick Cox
> Sent: 11 August 2004 10:30
> To: [email protected]
> Subject: st: RE: Multiple condition statement
>
>
> Yes; it is possible in one step. For example,
> you can use -cond()-. Some users love it, unconditionally,
> but others love it only under certain limited conditions.
>
> gen entry = cond(var1 == 0, entrydate,
> cond(var1 == 1, date1,
> cond(var1 == 2, date2,
> ...
> ))))))))))
>
> My layout here is designed to show structure, clearly.
> (or, structure clearly).
> To Stata this is all one command line. In a do-file
> or program, I would put some effort in laying it
> out neatly: otherwise I'd get lost somewhere in
> the middle. (There is a choice between commenting
> out ends of line and using -#delimit ;-.) But that
> takes time.
>
> At this point there are various reactions:
>
> 1. Great! I can do it in one line. Now how I
> do become a LISP programmer?
>
> 2. How do I check that my parentheses are all
> balanced? (Any decent text editor will do it.
> In Stata's do file editor, it's Ctrl-B. In Vim,
> it's %. ... (If you can't do this within your text
> editor, it is not a decent text editor (and
> if you are trying to do this in a word
> processor, that's a bad idea too).))
>
> 3. Nevertheless I wouldn't do your example this
> way, even though it has a pretty clear structure.
> Others might disagree: David Kantor is an
> articulate proponent of -cond()-, for example.
>
> I'd do it this way.
>
> gen entry = entrydate if var1 == 0
>
> forval i = 1/9 {
> replace entry = date`i' if var1 == `i'
> }
>
> Naturally you need to know about -forval-
> to do it like this. My recommendation assumes
> that, and also is based on the following:
>
> * This is more code, but I'm more likely
> to write it down correctly first time.
>
> * If I don't get it right first time,
> it is easier to fix.
>
> * This construct in do files, programs, and logs is
> going to be easier to understand and
> to modify when revisited days, months,
> years later. This is especially important
> if you work in groups and/or your files
> will be inherited or borrowed by others
> who want to understand them (or modify
> them).
>
> Nick
> [email protected]
>
> Another way is this:
>
> gen entry = (var1 == 0) * entrydate
> + (var1 == 1) * date1
> + (var1 == 2) * date2
> ...
> + (var1 == 9) * date9
>
> but you may still have to
>
> replace entry = . if entry == 0
>
> or at least
>
> assert entry > 0
>
> I'd still prefer the -forval- way,
> at least for examples like yours.
>
> Hannah Moore
>
> > Is it possible to have a multiple condition statement?
> >
> > I would like to generate a new variable:
> >
> > entry = entrydate if var1==0, date1 if var1==1, date2 if
> > var2==2.........., date9 if var9==9
> >
> > Can someone please tell me whether this is possible in 1 step, and
> > what the correct syntax would be?
>
> *
> * 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/
