Also
gen c = cond(a == ., b, a)
Nick
n.j.cox@durham.ac.uk
Maarten Buis
> gen c = a
> replace c = b if c==.
SamL
> I have two variables, a and b, and 1.5 datasets, A and B.
> All cases in B are in A, but some cases
> in A are not in B. I want to merge the two datasets,
> matching on the id.
>
> Variable a is missing for some cases in A, but the same
> variable has valid
> values for some of those cases in B (as b).
>
> I have tried several approaches. What I want is:
>
> do if (a ne .)
> compute c=a
> else if (b ne .)
> compute c=b
> else
> compute c=.
> end if
>
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