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From |
Johannes Geyer <JGeyer@diw.de> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
st: cycling through individual indices |

Date |
Wed, 17 Sep 2008 18:34:30 +0200 |

Dear Statalisters, I have Stata 10.1 IC and I try to create individual specific sums in a large dataset. The problem is a bit complicated and I have to cycle through all individuals and variables using the "in" qualifier. I am curious if anyone has an idea how to solve this problem more efficiently. Here is the problem: The data are in wide format and look like ID Agemonth Var_1 Var_2... ...Var_623 Var_624 1 532 2 2 14 14 2 345 7 7 14 Mis 3 236 3 3 Mis Mis 4 267 2 2 12 12 and so forth; there are about 50,000 observations. "Agemonth" indicates the observation period which is individual specific: "1" means January of the year after the person turned 14, "2" is February and so forth. That means e.g. "ID" 1 was observed 532 months after the year he/she turned 14. The index of the variables indicate the same time index. Thus, person 1 was observed from Var_1 until Var_532. Unfortunately, that does not mean that Var_533 or even Var_623 is missing but it may have a value like in the example above. Var_# has a number of distinct values and I need to sum them up in each case. If I had no invalid observations I could type egen sum1 = anycount(Var_*), values(1) However, then I count also invalid observations. I ended up with looping through individuals (~50,000) and variables (624), summing up one by one but I really doubt that this is the "best" solution (and hope that it is not): ******************* #d; gen sum1 = 0; sort ID; gen index = _n; qui sum index; forvalues indis = `r(min)'/`r(max)' {; di "`indis'"; forvalues f = 1/624 {; if `f' <=Agemonth in `indis' {; qui replace sum1 = sum1 + (Var_`f' == 1) in `indis'; }; }; }; ******************* Another possibilty would be to have the data in long format - however, since I have so many periods it takes a while to reshape the data, even in portions. I tried that with a 10% sample and "reshape" took more than one hour (maybe I have to ask for a better computer...). Any help would be appreciated! Thank you, Johannes ---------------------- Johannes Geyer Deutsches Institut für Wirtschaftsforschung (DIW Berlin) German Institute for Economic Research Department of Public Economics DIW Berlin Mohrenstraße 58 10117 Berlin Tel: +49-30-89789-258 owner-statalist@hsphsun2.harvard.edu schrieb am 17/09/2008 16:36:14: > Bill Gould has a Mata matters column out real soon now in Stata Journal > 8(3) 2008 that should help here. > > Nick > n.j.cox@durham.ac.uk > > -----Original Message----- > From: owner-statalist@hsphsun2.harvard.edu > [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Stas > Kolenikov > Sent: 17 September 2008 15:22 > To: statalist@hsphsun2.harvard.edu > Subject: st: analogues of macros in Mata? > > Suppose I form say a filename using some string operations, something > like > > myfilename = prefix + "-" + suffix > > and then want to save something along the lines of > > mata matsave {myfilename} Matrix1 Matrix2 Matrix3 > > Is there any way to have Mata go into the contents of myfilename > object there, rather than create the file "myfilename.mmat" in the > current directory? Or may be explicit version > > mata matsave prefix+"-"+suffix Matrix1 Matrix2 Matrix3 > > > * > * For searches and help try: > * http://www.stata.com/help.cgi?search > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**st: RE: cycling through individual indices***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

**References**:**st: RE: analogues of macros in Mata?***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

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