SV: st: Using values in an variable to save parts of an dataset

[Andreas Dall Frøseth <Andreas.Froseth@stud.nhh.no>]

It looks like I need some help with this code again...

After running this a couple of times, for different restrictions, I experience some difficulties. In addition to -keep-ing if industryid==`industryid', I wish to drop if the value in the variable "length" is less than a certain value. 
But, for some industryids there are no companies listed with a "length" over lets say 8, which leads to an error, and the do-file stops.

How can I make the code ignore those industries, and keep on splitting my dataset? 
 
-Andreas

________________________________________
Fra: owner-statalist@hsphsun2.harvard.edu [owner-statalist@hsphsun2.harvard.edu] på vegne av Andreas Dall Frøseth [Andreas.Froseth@stud.nhh.no]
Sendt: 30. april 2013 16:57
Til: statalist@hsphsun2.harvard.edu
Emne: SV: st: Using values in an variable to save parts of an dataset

I tried the approach where you exploited a feature of -use-, and it seems to work just fine.
Thank you.

-Andreas
________________________________________
Fra: owner-statalist@hsphsun2.harvard.edu [owner-statalist@hsphsun2.harvard.edu] på vegne av Nick Cox [njcoxstata@gmail.com]
Sendt: 30. april 2013 16:44
Til: statalist@hsphsun2.harvard.edu
Emne: Re: st: Using values in an variable to save parts of an dataset

Your local references are the wrong way round.

foreach industryid in `industryids' {
        keep if industryid==`industryid'
        save industry_`industryid'
}

You want each statement inside the loop to take on each individual value.

This is all assuming that -industryid- is numeric.

However, even with this fixed your loop won't work. Second time round,
all you have in memory is the first subset resulting from -keep-.

But then you can exploit a feature of -use-:

levelsof industryid, local(industryids)

foreach industryid in `industryids' {
        use mydata if industryid==`industryid', clear
        save industry_`industryid'
}


Nick
njcoxstata@gmail.com


On 30 April 2013 15:33, Andreas Dall Frøseth
<Andreas.Froseth@stud.nhh.no> wrote:
> Dear all.
>
> I'm trying to divide my dataset into pieces based on the values in an variable. My set is an large panel data, containing a number of companies. Each company has a value in the variable "industryid", which allows me to identify what industry it operates in.
> I am now trying to divide this large dataset into smaller sets for each single industry.
>
> The reason why I'm struggling is that I wish to apply this separation for a number of different sets, which might contain a different amount of industries, without having to identify the values in the industry-variable myself.
> I have tried to make a macro with the values using the "levelsof" command, and then apply it with:
>
> foreach industryid in `industryids' {
>         keep if industryid==`industryids'
>         save industry_`industryids'
> }
>
>
> But this runs back as "invalid '10'".
>
> Any suggestions on how to do this?
> Forgive me if this is way to basic...
>
> Your feedback will be appreciated.
>
> -Andreas
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