Adding in stata with some missing

[dee moks]

Hi I was wondering if anyone can help with coding. I'm struggling a bit with this.

I'm trying to add up a set of variables (9 in total) representing 9 different questions.

I want stata to add it if the respondent has answered atleast 6 of the 9 question but not to add it if it doesn't have atleast 6.

Can anyone please advise many Thanks

[Carlo Lazzaro]

Dee:
do you mean something along the following lines?:

. set obs 3
number of observations (_N) was 0, now 3

. g id=_n

. g A=1 in 1/2
(1 missing value generated)

. g B=1 in 2/3
(1 missing value generated)

. g C=1

. egen flag=rownonmiss(A B C)

. list

     +-----------------------+
     | id   A   B   C   flag |
     |-----------------------|
  1. |  1   1   .   1      2 |
  2. |  2   1   1   1      3 |
  3. |  3   .   1   1      2 |
     +-----------------------+

. keep if flag>=3
(2 observations deleted)

. list

     +-----------------------+
     | id   A   B   C   flag |
     |-----------------------|
  1. |  2   1   1   1      3 |
     +-----------------------+

.

[dee moks]

Thanks Carlo, not quite though. The question is a yes or no answer with yes=1 and no=0. I would also want it to add it up even if it has 6 no's

[Nick Cox]

Carlo Lazzaro has given you the main idea. His code is not broken by zeros in the data. Suppose your variables are A B C D E F G H I.

Then

egen present = rownonmiss(A B C D E F G H I) 
egen wanted  = rowtotal(A B C D E F G H I) if present >= 6

[Nick Cox]

That said, a row mean would appeal more to me here. Otherwise you are trying to compare (e.g.) a total of 6 from 6 and 6 from 9.