Re: st: RE: Need help with Programming/ running a forvalues loop inside foreach loop

[Michael Stewart <michaelstewartresearch@gmail.com>]

Dear Sergiy,

Thank you very much for your response.

Just to clarify your suggestions, the new loop looks a follows .Is this right??
The loop does well for var-1 (across all years) but after the cycle is
completed, it fails for second variable (var-2) and gives a error
saying "no; data in memory would be lost r(4);"

***********************************************
clear
macro drop _all
global data "Z:\data"
foreach outcome in  var1 var2 var3 {
local interesting "`outcome' var5 var6 var7"
use `interesting' "$data\dataset_1"
forvalues i=2/10{
append using "$data\dataset_`i'",keep(`interesting')
}
svyset [pweight= var5],strata  (var6 ) psu ( var7 )
svy:mean `outcome'
}
***************************************************
Do you have any recommendations to make the loop run for all variables
i.e., var1, var2 and var3  across all years .

Thank you very much for your time.

On Tue, Nov 5, 2013 at 4:34 PM, Joe Canner <jcanner1@jhmi.edu> wrote:
> Mike,
>
> I don't see anything particularly wrong with the -forvalues- loop, but I think the -use- statement should also have a -using-:
>
> use `x' var5 var6 var7 using "$data\dataset_1",clear
>
> That aside, what specific symptoms are you seeing when you do the -forvalues- loop?  Are you getting errors?  What is in memory when it finishes?
>
> Regards,
> Joe Canner
> Johns Hopkins University School of Medicine
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Michael Stewart
> Sent: Tuesday, November 05, 2013 3:42 PM
> To: statalist
> Subject: st: Need help with Programming/ running a forvalues loop inside foreach loop
>
> Dear Statalist member,
>
> I am writing to seek help with stata programming and I am dealing with
> rather large datasets and am resorting to loading relevant variables
> of the dataset for analysis secondary to memory constraint.
>
> I especialy need help running a  forvalues loop inside a foreach loop .
>
> Details are as follows :
> *************************
> My data is in a folder "Z:data"
>
> My files are named dataset_1 to dataset_10 (denoting years 2001 till
> 2010) and each file is in the order of  gigabytes with 40 variables
> each .
>
> For my analysis I have to use (either var1 OR var2 OR var3) along with
> (var5+var6+var7) from each dataset.
>
> As it is a multiyear analysis, I need to combine (either var1 OR var2
> OR var3) along with (var5+var6+var7) from each dataset(dataset_1 to
> dataset_10) and analyze.
>
>
> My  dofiles is as follows
>
> *******************************
> clear
> macro drop _all
> global data "Z:data"
>
> foreach x in  var1 var2 var3 {
> use `x' var5 var6 var7 "$data\dataset_1",clear
> forvalues i=2/10{
> append using "$data\dataset_`i'",keep(`x' var5 var6 var7  )
>
> }
> svyset [pweight= var5],strata  (var6 ) psu ( var7 )
> svy:mean `x'
>
> }
> *************************************************************
>
> QUESTION:  How can I make the forvalues loop  merge only relevant
> variables from each dataset into one big dataset  before proceeding to
> the next step so that I will have multi year dataset for analysis at
> subsequent steps
>
> To further clarify the question:
>
> After the foreach loop  takes var1 + var 5-7 from dataset_1; I would
> like the forvalues loop to take var1 + var 5-7 from dataset_2/10 ,
> merge them and procedd further statistical analysis.
>
> In next cycle, the foreach loop will take var2 + var 5-7 from
> dataset_1; I would like the forvalues loop to take var2 + var 5-7 from
> dataset_2/10 , merge them and procedd further statistical analysis.
>
> But with my loop, the forvalues loop is not merging multipe
> files(dataset_2 to dataset_10) before proceeding for furtehr analysis.
>
> Any suggestions/recommendations are welcome
>
> Thank you very much for your time.
>
> --
> Thank you ,
> Yours Sincerely,
> Mike.
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-- 
Thank you ,
Yours Sincerely,
Mike.
*
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*   http://www.ats.ucla.edu/stat/stata/