Re: st: counting variables within a row

[Sarah Elizabeth Edgington <sedging@ucla.edu>]

Casey,
You could use a foreach loop to assess your criteria for each 
variable and then add 1 to a count variable if it's true.  To save 
myself some typing I'm going to assume a simpler case where you only 
have five variables but you can extend it beyond that to the full 
eighteen (note that if you were using variable names with a numeric 
suffix like met_a1 you could use a forvalues loop).
To get your first count it might look something like this:

gen lightcount_d1=0
foreach num in one two three four five {
        replace lightcount_d1=lightcount_d1+1 if met_a`num'>0 & met_a`num'<3
}

There may be other ways to do this but this is the first that occurs to me.

-Sarah

At 04:15 PM 6/8/2010, you wrote:
> Hi folks,
>
> I have a dataset with 18 variables called met_aone-met_aeighteen.
> Within each observation, I'm trying to count the number of these
> variables with values which satisfy three criteria.  I thought I could
> handle this with -egen- and the lines of code I originally wrote are:
>
> egen lightcount_d1= rownonmiss ( met_aone-met_aeighteen) if (
> met_aone-met_aeighteen)> 0 & ( met_aone-met_aeighteen)< 3
> egen modcount_d1= rownonmiss (met_aone-met_aeighteen) if
> (met_aone-met_aeighteen)>= 3.0000 & (met_aone-met_aeighteen)< 6
> egen hardcount_d1= rownonmiss (met_aone-met_aeighteen) if
> (met_aone-met_aeighteen)>= 6.0000 & (met_aone-met_aeighteen)< .
>
> The problem as I quickly realized is that it is only counting
> variables when every single value in the row satisfies the if
> requirement.  What I can't figure out is how to assess each variable
> individually for meeting the criteria, but ultimately producing a new
> variable with the total within the observation which meets my
> criteria.
>
> Any thoughts on how to handle this?
>
> Thanks in advance.
>
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