separate number (string variable) in digits

[lisa bäcker]

Hello,

I need some help please. I have a string variable which is a number, each digit of the number has a meaning and I need to seperate the digits.
But not all numbers contain the same number of digits..
I just need the first digits of the number.
Do you have an idea how I can seperate the number?

Thanks in advance
Lisa

[Nick Cox]

Absent an example of your data, here is a sandbox and some technique:

clear 
set obs 5 
gen mystrvar = substr("a1c2e", 1, _n) 
list 
forval j = 1/5 { 
    gen char`j' = substr(mystrvar, `j', 1) 
} 
list

which gives

. clear 

. set obs 5 
obs was 0, now 5

. gen mystrvar = substr("a1c2e", 1, _n) 

. list 

     +----------+
     | mystrvar |
     |----------|
  1. |        a |
  2. |       a1 |
  3. |      a1c |
  4. |     a1c2 |
  5. |    a1c2e |
     +----------+

. forval j = 1/5 { 
  2.     gen char`j' = substr(mystrvar, `j', 1) 
  3. } 
(1 missing value generated)
(2 missing values generated)
(3 missing values generated)
(4 missing values generated)

. list 

     +--------------------------------------------------+
     | mystrvar   char1   char2   char3   char4   char5 |
     |--------------------------------------------------|
  1. |        a       a                                 |
  2. |       a1       a       1                         |
  3. |      a1c       a       1       c                 |
  4. |     a1c2       a       1       c       2         |
  5. |    a1c2e       a       1       c       2       e |
     +--------------------------------------------------+

Once past the first session, users need to know about the basic functions. One tutorial is at

http://www.stata-journal.com/article...article=dm0058

[lisa bäcker]

hello nick,
thanks for your help and also for your paper.
just one more question, is it easier to seperate the digits if I do not have a string variable?
how does it work in this case?
sorry for this kind of basic questions, but for me it is really dificult to work with stata..

[Nick Cox]

No. With a numeric variable it is not easier. It is easier to work on the string equivalent.