Create id variable

[Stefano Ciola]

Dear Stata experts,

I'm new to stata and need some help for my analysis.
This is my problem:
I've a dataset made of by 17 variables (Year, Winter, spring, summer, autumn, january, february, march, april, may, ..... december).
All these variables refer to a specific weather station. There are 8 weather stations (8 .dta files).
For each weather station there are the same 17 variables, but with different values.
I want to create a id variable for each dta file with name of weather station.

I hope I was clear.
I'm grateful for all the help you can give.

[Rich Goldstein]

for each file you need something like:

gen id = "Boston"

replace Boston with the name of the weather station

I assume you will then append the 8 files into one, correct?

note that further advice is probably possible if one knows more about your data and where you are going; the FAQ has advice on asking questions and you should read it

[Stefano Ciola]

Thank Rich, It's correct.
Sorry i'll read the FAQ

[Jorrit Gosens]

An automated way of creating the id variable and appending all the fiels, which is what you seem to want, is:

**change directory to the directory holding your dta files
cd "C\somepath\"
clear
**create list of all dta files in that directory**
local myfilelist : dir . files "*.dta"

**For each of the files, generate an id variable
foreach file of local myfilelist {
clear
use `file'
local fileid = subinstr("`file'",".dta","",8) 
gen id="`fileid'" 
save `file', replace 
}
clear
**append the files into one file.
foreach file of local myfilelist{
append using `file'
save appended, replace
}