Anek,
Stata isn't SPSS!
You have used the command -if-, which is intended for programmers. Your code
checks, whether the first observation in the variable "certification" has the
value of 1. If so, the replace commands are executed for _all_ observation in
the data. Most likely this is not what you wanted.
Moreover, in SPSS "generating" and "replacing" can be done with the same
command. In Stata there are two. -generate- generates a new variable,
-replace- changes the contents of an existing variable. You cannot generate a
non-existing variable with -replace-.
All togheter what you want might be something like this:
gen age = 22 if age <= 5 & certification == 1 ;
replace age = 30 if age >= 6 & age <= 15 & certification == 1 ;
replace age = 40 if age >= 16 & age <= 20 & certification == 1 ;
replace age = 50 if age > 20 & certification == 1 ;
replace age = 22 if age <= 3 & certification == 2 ;
replace age = 30 if age >= 4 & age <= 13 & certification == 2 ;
replace age = 40 if age >= 14 & age <= 24 & certification == 2 ;
replace age = 50 if inlist(age,25,26,27,28) & certification == 2 ;
Hope this helps.
Uli
Anek Stata wrote:
> Greetings everyone,
>
> I am using Stata 8.1 on Win2000. My data set contains variable
> "certification", which takes values 1 or 2 only. I am trying to group
> respondents from these two "certification" sets into age groups. For SOME
> REASON, the if command for certification==1 executes all the replace
> commands, but when it goes to the second if, none of the replace commands
> within the curly brackets get executed.
>
> Below is the code I am using:
> ----------------------------------------
>
> if certification == 1 { ;
> replace age = 22 if age <= 5;
> replace age = 30 if age >= 6 & age <= 15;
> replace age = 40 if age >= 16 & age <= 20;
> replace age = 50 if age > 20;
> { ;
> else if certification == 2 { ;
> replace age = 22 if age <= 3;
> replace age = 30 if age >= 4 & age <= 13;
> replace age = 40 if age >= 14 & age <= 24;
> replace age = 50 if age == 25;
> replace age = 50 if age == 26;
> replace age = 50 if age == 27;
> replace age = 50 if age == 28;
> };
>
> ----------------
> I have tried to break it on purpose, writing "if certification==3". This
> gives me NO ERRORS, even though there is never a value 3 in variable
> certification. This is obviously wrong. I have also tried the code with and
> without "else" (just trying to execute another if), to no avail. I've
> tried:
>
> ...
> replace age = 50 if age > 20;
> };
> else{;
> replace age = 22 if age <= 3;
> ...
>
> and
>
> ...
> replace age = 50 if age > 20;
> };
> if certification==2{;
> replace age = 22 if age <= 3;
> ...
>
>
> Since the help file is USELESS, I'd like to ask for your help, if you can
> spot what I am doing wrong.
>
> Thanks a lot,
> Ane
>
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